NREL is a national laboratory of the U.S. Department of Energy

Office of Energy Efficiency & Renewable Energy

Operated by the Alliance for Sustainable Energy, LLC

This report is available at no cost from the National Renewable Energy

Laboratory (NREL) at www.nrel.gov/publications.

Contract No. DE-AC36-08GO28308

Technical Report

NREL/TP-5K00-73041

January 2019

Rapid Development of Disruptive 

Photovoltaic Technologies

Andriy Zakutayev

National Renewable Energy Laboratory
NREL is a national laboratory of the U.S. Department of Energy

Office of Energy Efficiency & Renewable Energy

Operated by the Alliance for Sustainable Energy, LLC

This report is available at no cost from the National Renewable Energy

Laboratory (NREL) at www.nrel.gov/publications.

Contract No. DE-AC36-08GO28308

National Renewable Energy Laboratory

15013 Denver West Parkway

Golden, CO 80401

303-275-3000 • www.nrel.gov

Technical Report

NREL/TP-5K00-73041

January 2019

Rapid Development of Disruptive 

Photovoltaic Technologies

Andriy Zakutayev

National Renewable Energy Laboratory

Suggested Citation

Zakutayev, Andriy. 2019. Rapid Development of Disruptive Photovoltaic Technologies. 

Golden, CO: National Renewable Energy Laboratory. NREL/TP-5K00-73041. 

https://www.nrel.gov/docs/fy19osti/73041.pdf.
NOTICE

This work was authored by the National Renewable Energy Laboratory, operated by Alliance for Sustainable 

Energy, LLC, for the U.S. Department of Energy (DOE) under Contract No. DE-AC36-08GO28308. Funding 

provided by U.S. Department of Energy Office of Energy Efficiency and Renewable Energy Solar Energy 

Technologies Office. The views expressed herein do not necessarily represent the views of the DOE or the U.S. 

Government.

This report is available at no cost from the National Renewable 

Energy Laboratory (NREL) at www.nrel.gov/publications.

U.S. Department of Energy (DOE) reports produced after 1991 

and a growing number of pre-1991 documents are available 

free via www.OSTI.gov.

Cover Photos by Dennis Schroeder: (clockwise, left to right) NREL 51934, NREL 45897, NREL 42160, NREL 45891, NREL 48097, 

NREL 46526.

NREL prints on paper that contains recycled content.
1

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Project Period: 1 Oct 2015 – 30 Sept 2018

Project Budget: $1,660,000

Submission Date: 28 September 2018

Recipient: National Renewable Energy Laboratory

Address: 15013 Denver West Pkwy, Golden, CO 80401

Agreement Number: SuNLaMP 30302

Awarding Agency: DOE EERE SETO PV subprogram

Working Partners: Colorado School of Mines

Principal Investigator: Andriy Zakutayev

Scientist

Phone: 303-384-6467

Email: andriy.zakutayev@nrel.gov
2

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Executive Summary

Development of new PV technologies based on novel materials is an important direction of solar 

cell research to enhance the odds for beyond-TW scaling of solar energy production. However, 

such research presents a significant technical challenge, because it requires a balance between 

sufficient breadth (screening new materials) and depth (development of PV devices) of the 

problem. The objective of this project was to establish novel inorganic photovoltaic absorbers 

using rapid development approach. The studied materials were the potentially scalable defecttolerant oxide- and nitride solar cell absorbers. For one of these materials (ZnSnN2), we have 

experimentally demonstrated how to achieve low carrier density required for solar cell 

fabrication, and demonstrated that this synthesis process leads to near band edge 

photoluminescence supporting high optoelectronic quality of the material. For this ZnSnN2

material, we also showed that cation disorder does not significantly influence carrier transport, 

and that benign defect complexes can lead to improved doping control, both supporting the 

targeted defect tolerance of this material. All these results have been summarized in peer review 

publications, some featured on journal covers. In addition, we established a new class of antiperovskite absorbers, and published several review articles of the field. 

Background

Development of new PV technologies based on novel materials could create a new industry with 

independent supply chains, foster market diversification, and attenuate market volatility. All 

these factors can enhance the odds for beyond-TW scaling of solar energy production. Such 

disruptive PV technologies must be competitive with current technologies in efficiency, cost, and 

reliability, and they should use readily available elements. In addition, they also have to be 

compatible with low-capex production processes to ensure rapid industry growth after initial 

commercialization.

Developing new PV absorber technologies is a significant technical challenge, because it 

requires a balance between sufficient breadth (screening new materials) and depth (development 

of PV devices) of research. These technical hurdles are addressed by the complementary use of 

computational materials science and experimental synthesis/characterization techniques, both 

part of the Rapid Development approach. With this approach, the project can span the entire PV 

development cycle, from materials exploration, through targeted research on individual 

materials, to device integration.1

One class of emerging PV absorbers studied in literature have some resemblance to existing PV 

technologies and reported measurable efficiencies. Examples of such emerging PV absorber 

materials discussed below include binary chalcogenides related to CdTe (e.g., SnS2, Sb2Se33), 

copper chalcogenides related to CIGS (e.g., Cu2SnS3,

4 CuSbSe25), and emerging absorber 

materials related to MAPI. These absorbers have been recently reviewed as a part of this 

project.6

The other class is the emerging PV absorbers for which high-performing prototype solar cells 

have not been reported. One example is emerging PV technologies that feature new absorber 

physics, including multiple exciton generation,7 hot-carrier extraction,8 ferroelectric 

photovoltaics,

9 and so on. Another example includes new absorber chemistries with conventional 
3

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

absorber physics, such as oxides,

10 nitrides,1112 and mixed-anion compounds. This last group is 

in the focus of this project.

Introduction

The goal of this project was to develop defect-tolerant oxide- and nitride absorbers for 

photovoltaic solar cells technologies, that can be manufactured using commercial sputtering 

equipment common for the flat-panel-display or architectural-glass-coating industries. The 

defect-tolerant absorber materials in focus of this project were ZnSnN2 compounds and (Sn,Zn)O 

alloys, as well as emerging antiperovskite and wurtzite Mg-Sb-N materials. These novel 

absorbers are turned into PV technologies using the Rapid Development approach that combines 

high-throughput experimentation and high-accuracy calculations, demonstrated in the past on the 

example of novel Cu2SnS3 absorbers4 and CuSbS2 solar cells5

.

The project consisted of three periods, with two tasks, two progress indicators, and one milestone 

per period (on average). In the first period, we performed research to down-select from two to 

one absorber candidates. In the second period, the project focused on improving the

optoelectronic quality of the selected absorber, with additional tasks on technoeconomic 

analysis, and on theoretical exploration of the next-generation of absorbers. In the third period, 

we worked towards establishing a photoresponse from the absorbers, and synthesizing the most 

promising next-generation absorber materials identified by theory. 

Project Results and Discussion

Doping control is necessary to unlock the 

technological potential of the ZnSnN2 (ZTN) 

semiconductors. It has been demonstrated 

experimentally that a reduction of the carrier 

densities towards semiconducting nondegenerate level below 1017 cm-3 can be 

achieved in oxygen-containing and Zn-rich 

ZTN samples. This is theoretically 

unexpected, because ZnSn has very high 

formation energy throughout the band gap,

and because oxygen contamination usually 

contributes electrons in nitrides. To explain 

the unusual ZTN material properties, we 

developed an approach to go beyond the 

conventional defect model by considering the 

additional effects of non-equilibrium 

synthesis, off-stoichiometry, disorder, and (intentional or unintentional) incorporation of 

impurities, thereby capturing the physics of non-ideal complex mixed-ion semiconductor 

materials.

13 The ZTN calculations results (Fig.1) show that the net doping is a non-monotononic 

function of the Zn and O content, which has been considered as anomalous/unusual in the past.

The non-monotonic behavior is mainly due to the composition induced changes in the electronic 

structure, namely change in the band position and the resulting change in defect formation 

enthalpies at high Zn and O content. This mechanism allows the reduction of the free carrier 

Fig. 1. ZnSnN2 electronic structure and doping 

as a function of O and Zn content
4

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

density in highly off-stoichiometric Zn-rich samples, particularly when grown with activated N 

sources.

Beside the cation stoichiometry control of the doping, 

we showed that annealing Zn-rich ZnSnN2 grown 

with added hydrogen reduces its free electron density 

by two orders of magnitude, down to 4 x 1016 cm-3

. 

As shown in Fig. 2, zinc-rich Zn1+xSn1-xN2 (ZTN) has 

electron concentration of 2 x 1018 cm-3. The electron 

density of ZTN was reduced down to 2 x 1017 cm-3 , 

either upon annealing or as a result of growth in 

activated forming gas atmosphere. Most importantly, 

for ZTN films grown in forming gas and then 

annealed, the electron density decreased down to 4 x 

1016 cm-3

, suitable for formation of rectifying p-n 

junctions that can be used for solar cell application.14

This doping is a factor of 100 lower compared to asdeposited N2-grown films, and a factor of 10,000 

compared to what is typically reported in literature. 

This experimental observation can be explained by 

hydrogen passivation of acceptors in Zn1+xSn1-xN2 during growth, lowering the driving force for 

unintentional donor formation, followed by selective hydrogen removal by annealing. These 

results indicate that the doping control principles used in GaN can be translated to ZnSnN2, 

suggesting that other strategies used in binary III-Vs can be applied to accelerate the 

development of ternary II-IV-N2 materials studied in this project.

In multinary compound semiconductors like ZnSnN2, 

cation disorder can decisively alter the optoelectronic 

properties and impact potential solar cell applications. 

In the ground state structure of ZnSnN2, every N anion 

is coordinated by 2 Zn and 2 Sn cations, forming an 

ordered network tetrahedral motifs that locally observe 

the octet rule. Using a motif-based model Hamiltonian, 

we performed Monte-Carlo simulations that provide 

atomistic representations of ZnSnN2 with varying 

degrees of cation disorder. Subsequent electronic 

structure calculations were used to describe the 

evolution of band gaps, optical properties and carrier 

localization effects as function of the disorder.15 We 

find that octet-rule conserving disorder is practically 

impossible to avoid, but perfectly benign with hardly 

any effects on the electronic structure. In contrast, a 

fully random cation distribution would be very 

detrimental, but fortunately it is energetically highly unfavorable. The degree of disorder that can 

realistically be expected for non-equilibrium thin-film deposition (10 - 20% concentration of 

non-equilibrium motifs) leads to a moderate band gap reduction and small carrier localization 

effects. Comparing these results of theoretical simulations with experimental samples grown by 

Fig.3 Experimental absorption 

spectrum in Zn-rich ZnSnN2 in 

comparison with calculated 

absorption spectrum for ZnSnN2 in 

the fully ordered (SG 33) and 

partially disordered structure 

Fig.2 Carrier density as a function of 

hydrogen available during growth 

and labeled with post-growth 

treatment
5

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

sputtering and characterized by synchrotron x-ray diffraction patterns and by the optical 

absorption spectra (Fig. 3), we indeed find evidence of a certain degree (10-20%) of octet-rule 

violating cation disorder. This study demonstrates that the optoelectronic properties of ZnSnN2

are affected by the local coordination environments, and that the observed degree of cation 

disorder is likely to be acceptable for the solar cell absorber applications of this material. 

In addition to optoelectronic properties and doping 

control, good electronic structure properties are 

required from solar cell absorber materials. Thus, we 

performed a detailed investigation into the structural 

and electronic properties of low carrier density, zincrich ZTN films with Zn/(Zn+Sn)=0.67, by a 

combination of theory and experiment.16 Using high 

resolution XRD measurements and simulated MonteCarlo structural models, it was determined that zincrich ZTN is stabilized by the presence of oxygen, thus 

forming an alloy between ZnSnN2 and ZnO. 

Calculated defect formation energies demonstrated 

that formation of electronically benign ZnSn+2ON

complexes were the atomistic mechanism behind 

oxygen-stabilization of the zinc-rich structure. Low 

temperature, temperature-dependent, and power-dependent photoluminescence (PL) 

measurements identified a bound exciton transition in annealed ZTN films (Fig. 4), and these 

data allowed the bandgap in this material to be estimated at 1.54 eV. Observation of the exciton 

luminescence in polycrystalline thin film samples was explained by the formation of neutral 

defect complexes upon annealing, resulting in improved electronic quality of the material. 

Ultimately, the results of this work suggest that ZTN material with both low carrier density and 

good electronic structure properties can be achieved through a combination of zinc-rich growth, 

beneficial oxygen incorporation, and post-growth annealing.

To get further insight into electronic structure and 

charge carrier transport properties in ZnSnN2, we 

studied this material experimentally using temperaturedependent Hall effect measurements.17 The results of 

the carrier concentration and mobility measurement

were modeled using a combination of three scattering 

mechanisms, namely neutral defect scattering, ionized 

defect scattering and grain boundary scattering (Fig.5). 

The results of these research efforts indicate that at

PV-relevant conditions (Room-Temperature 

measurement on Zn-rich samples), the electron

mobility is limited by scattering on neutral defects. 

Combined with the results of the first principle 

calculations described above, the most likely 

microscopic origin of this neutral defect scattering is 

the ZnSn+2ON defect complex. Another conclusion 

from the experimental measuring and modeling is that 

the ZTN samples can be described highly compensated semiconductors, with electron density 

Fig.4 Temperature-dependent PL of 

the annealed, zinc-rich sample with 

Zn/(Zn+Sn)=0.67

Fig.5 Contribution of different 

possible scattering mechanisms to 

the inverse electron mobility vs.

measurement temperature
6

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being orders of magnitude lower than the dopant densities. These results are consistent with the 

composition estimates obtained from the combination of XRF, SIMS and RBS measurements, 

which show that the zinc and oxygen concentration are proportional to each other at PV-relevant 

Zn-rich composition range with low carrier density. 

While carrier concentration of ZTN has been reduced to 

values suitable for device implementation, other properties 

such as ionization potential, electron affinity and work 

function were not known. We used Kelvin probe and 

Photoemission spectroscopy measurements to determine 

the ionization potential (5.6 eV), electron affinity (4.1 eV) 

and work function (4.4 eV) for ZTN thin film samples with 

Zn/(Zn+Sn) = 0.56.18 These values would imply that ntype ZTN forms a cliff-type valence band offset with NiO 

and CuCrO2 p-type contacts. Further, using both 

experimental and theoretical results, we built a device 

model to simulate the performance of a ZTN/Mg:CuCrO2

solar cell, showing a potential efficiency of 23% in the 

limit of no defects present. The effect of the position of the 

band edges of the p-type junction partner was assessed in 

the presence of band tails and defect states (Fig. 6). It was 

found that for this n-type ZTN absorber with relatively low hole mobility and with the 

aforementioned imperfections, the spike band offset is more detrimental than the cliff band 

offset, in contrast to solar cells with CdTe or CIGS absorbers. Through this modeling study, we 

determined the major bottlenecks for the development of ZTN-based solar cell and identified 

avenues to mitigate them.

Besides the mainstream work on ZnSnN2, in this 

project we evaluated several other new absorbers, 

down-selected them using theoretical methods, and 

synthesized some of them. For example, a highthroughput experimental investigation of the 

computationally predicted Mg-Sb-N ternary system

was carried out.

19 The Mg-Sb-N ternary system 

was predicted to have three ternary materials, 

including Mg3SbN anti-perovskite with promising 

PV absorber properties, and previously unreported 

Mg2SbN3 with wurtzite-like structure. In particular, 

for the Mg3SbN, the effective masses of both 

electrons and holes are calculated to be <1 m0 and 

the relative dielectric constant is 27, which the band 

gap is slightly indirect (1.1 eV) and absorption onset is 0.2 eV higher in energy (Fig. 7). The 

synthesis was performed using radio-frequency magnetron co-sputtering of Mg and Sb in N 

plasma, and the synthesis phase map has been created. A crystalline form of wurtzite-like 

Mg2SbN3 has been synthesized for the first time, consistent in structure with the first principles 

theory prediction. Similarly, Mg3SbN anti-perovskite has been synthesized in thin film form for 

the first time, facilitating a range of new metrology of this material. Optoelectronic 

characterization was carried out across this ternary system, confirming the 1.4 eV optical 

Fig. 6. Simulated JV curves of the 

ZTN/ Mg:CuCrO2 heterojunction 

as a function of increasing IP of 

Mg:CuCrO2

Fig. 7. Optical properties of Mg3SbN
7

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absorption onset for Mg3SbN, and room-temperature photoluminescence (Fig.7). These 

experimental results support the promise of Mg3SbN anti-perovskite as a photovoltaic absorber 

material.

Conclusions

We theoretically explained that the carrier density in ZnSnN2 decreases to 1017 cm–3 with 

increasing Zn and O content due to formation of defect complexes and modification of the 

material electronic structure.13 Further, we experimentally showed that annealing Zn1+xSn1–xN2

grown with added hydrogen reduces its free electron density by orders of magnitude, down to 4 

× 1016 cm–3. 14 These carrier densities are low enough for formation of rectifying heterojunctions 

necessary for solar cell fabrication, according to modeling.18

We also calculated that octet-rule conserving disorder in ZnSnN2 is practically impossible to 

avoid but has hardly any effects on the electronic structure.

15 These theoretical results were 

supported by experimental measurements of near band edge photoluminescence in the annealed 

material.16 Finally, we experimentally determine the value of ionization potential, electron 

affinity, and work function for Zn1+xSn1–xN2 (ZTN) thin film samples.

17

In addition to work on ZnSnN2, we also discovered a new wurtzite-like Mg2SbN3 material in 

Mg-Sb-N system and reported for the first time on optoelectronic properties of Mg3SbN

antiperovskite.19 All these results were summarized in many peer review publications (see 

complete list below). We also published a few review papers on nitrides and emerging PV 

absorbers in FY16-18 project,

6,12 and finalized publications from the previous FY13-15 project 

period (also listed below).

20,21,22

Budget and Schedule

The total budget of the project is $1,660,000 over the three years, with 100% federal share. The 

project consisted of three budget periods, one year each starting FY16. There were not 

significant schedule or cost modifications during the cost of the project.

Path Forward

Plans for future research and development include collaboration with industrial partners, and 

work funded by other parts of DOE. The industrial collaborations would use the rapid 

development approaches of this project to other solar cell technologies, outside of absorber layer.

The work with other part of DOE would be on applications unrelated to solar photovoltaic 

technologies, where new materials challenges are present.
8

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

Publications Resulting from This Work

The publication listed from the FY16-18 work period are listed below:

A. N. Fioretti, A. Stokes, M. R. Young, B. Gorman, E. S. Toberer, A. C. Tamboli, and A. 

Zakutayev, Effects of Hydrogen on Acceptor Activation in Ternary Nitride Semiconductors, 

Advanced Electronic Materials, 3, 1600544 (2017) – highlighted on journal front cover 

S. Lany, A. N. Fioretti, P. P. Zawadzki, L. T. Schelhas, E. S. Toberer, A. Zakutayev, and A. C. 

Tamboli, Monte Carlo simulations of disorder in ZnSnN2 and the effects on the electronic 

structure, Physical Review Materials 1, 035401 (2017)

E. Arca, A. Fioretti, S. Lany, A. C. Tamboli, G. Teeter, C. Melamed, J. Pan, K. N. Wood, E. 

Toberer, and A. Zakutayev. "Band Edge Positions and Their Impact on the Simulated Device 

Performance of ZnSnN2-Based Solar Cells." Invited Article - IEEE Journal of Photovoltaics 8, 

110 (2018)

Fioretti, A.N., Pan, J., Ortiz, B.R., Melamed, C.L., Dippo, P.C., Schelhas, L.T., Perkins, J.D., 

Kuciauskas, D., Lany, S., Zakutayev, A. Toberer, E.S., Tamboli, A.C., Exciton 

photoluminescence and benign defect complex formation in zinc tin nitride, Materials Horizons 

5, 823 (2018) – highlighted on journal inside front cover 

A. Zakutayev, Brief review of emerging photovoltaic absorbers, Current Opinion in Green and 

Sustainable Chemistry, 4, 8, (2017) 

AD Martinez, AN Fioretti, ES Toberer, AC Tamboli et al Synthesis, structure, and optoelectronic 

properties of II–IV–V 2 Journal of Materials Chemistry A 5 (23), 11418-11435 (2017)

J. Pan, J. Cordell, G. J. Tucker, A. Tamboli, A. Zakutayev, S. Lany, Interplay between 

composition, electronic structure, disorder, and doping due to dual sublattice mixing in nonequilibrium synthesis of ZnSnN2:O, Advanced Materials, in press

D. Hamilton, E. Arca, J. Pan, S. Siol, M. Young, S. Lany, A. Zakutayev, Electron scattering 

mechanisms in zinc tin nitride, submitted

Publications from FY13-15 work period, that appeared during FY16-18 work period, and were 

not reported before, are listed next:

de Souza Lucas, F.W. and Zakutayev, A. Research Update: Emerging chalcostibite absorbers for 

thin-film solar cells, APL Materials, 6 084501 (2018)

K. Heinselman, J. Perkins, S. Lany, A. Zakutayev “New PV absorber materials in Mg-Sb-N 

system”, in preparation

Birkett, M., Savory, C.N., Rajpalke, M.K., Linhart, W.M., Whittles, T.J., Gibbon, J.T., Welch, 

A.W., Mitrovic, I.Z., Zakutayev, A., Scanlon, D.O. and Veal, T.D..Band gap temperaturedependence and exciton-like state in copper antimony sulphide, CuSbS2, APL Materials, 6, 

084904 (2018)
9

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

T. J. Whittles, T. D. Veal, C. N. Savory, A. W. Welch, F. W. de Souza Lucas, J. T. Gibbon, M. 

Birkett, R. J. Potter, D. O. Scanlon, A. Zakutayev, and V. R. Dhanak, Core Levels, Band 

Alignments, and Valence-Band States in CuSbS2 for Solar Cell Applications, ACS Appl. Mater. 

Interfaces, 9, 41916 (2017)

F. W. de Souza Lucas, H. Peng, S. Johnston, P. C. Dippo, S. Lany, L. H. Mascaro, A. Zakutayev, 

Characterization of defects in copper antimony disulfide, Journal of Materials Chemistry A 5, 

21986, (2017)
10

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

References

1 S. Lany, T. Gershon and A. Zakutayev, Advanced materials for solar energy conversion, in

“Roadmap on optical energy conversion”, Journal of Optics, 18, 073004 (2016)

2 J. Andrade-Arvizu, M. Courel-Piedrahita, SnS-based thin film solar cells: Perspectives over the 

last 25 years, Journal of Materials Science: Materials in Electronics 26.7 (2015): 4541-4556.

3 K. Zeng, D.-J. Xue, J. Tang, Antimony selenide thin-film solar cells, Semicond. Sci. Technol. 

31 (2016) 63001. 

4 L. L Baranowski, P. Zawadzki, S. Lany, E.S. Toberer and A.Zakutayev, A review of defects 

and disorder in multinary tetrahedrally bonded semiconductors, Semicond. Sci. Technol. 31 

123004 (2016)

5 de Souza Lucas, F.W. and Zakutayev, A., Research Update: Emerging chalcostibite absorbers 

for thin-film solar cells., APL Materials, 6 084501 (2018)

6 Andriy Zakutayev, Brief review of emerging photovoltaicabsorber materials, Current Opinion 

in Green and Sustainable Chemistry, 4, 8, (2017)

7 M.C. Beard, Multiple exciton generation in semiconductor quantum dots, J. Phys. Chem. Lett. 

2 (2011) 1282–1288

8 D. König, K. Casalenuovo, Y. Takeda, G. Conibeer, J.F. Guillemoles, R. Patterson, L.M. 

Huang, M.A. Green, Hot carrier solar cells: Principles, materials and design, Phys. E LowDimensional Syst. Nanostructures. 42 (2010) 2862–2866. 

9 K.T. Butler, J.M. Frost, A. Walsh, Ferroelectric materials for solar energy conversion: 

Photoferroics revisited, Energy Environ. Sci. 8 (2015) 838–848. 

10 S. Rühle, A.Y. Anderson, H.-N. Barad, B. Kupfer, Y. Bouhadana, E. Rosh-Hodesh, A. Zaban, 

All-oxide photovoltaics, J. Phys. Chem. Lett. 3 (2012) 3755–3764. 

11 A. Zakutayev, Design of nitride semiconductors for solar energy conversion, Journal of 

Materials Chemistry A 4.18 (2016): 6742-6754.

12 AD Martinez, AN Fioretti, ES Toberer, AC Tamboli et al Synthesis, structure, and 

optoelectronic properties of II–IV–V 2 Journal of Materials Chemistry A 5 (23), 11418-11435 

(2017)

13 J. Pan, J. Cordell, G. J. Tucker, A. Tamboli, A. Zakutayev, S. Lany, Interplay between 

composition, electronic structure, disorder, and doping due to dual sublattice mixing in nonequilibrium synthesis of ZnSnN2:O, Advanced Materials, in press

 
11

This report is available at no cost from the National Renewable Energy Laboratory (NREL) at www.nrel.gov/publications.

 14 A. N. Fioretti, A. Stokes, M. R. Young, B. Gorman, E. S. Toberer, A. C. Tamboli, and A. 

Zakutayev, Effects of Hydrogen on Acceptor Activation in Ternary Nitride Semiconductors, 

Advanced Electronic Materials, 3, 1600544 (2017)

15 S. Lany, A. N. Fioretti, P. P. Zawadzki, L. T. Schelhas, E. S. Toberer, A. Zakutayev, and A. C. 

Tamboli, Monte Carlo simulations of disorder in ZnSnN2 and the effects on the electronic 

structure, Physical Review Materials 1, 035401 (2017)

16 Fioretti, A.N., Pan, J., Ortiz, B.R., Melamed, C.L., Dippo, P.C., Schelhas, L.T., Perkins, J.D., 

Kuciauskas, D., Lany, S., Zakutayev, A. Toberer, E.S., Tamboli, A.C., Exciton 

photoluminescence and benign defect complex formation in zinc tin nitride, Materials Horizons 

5, 823 (2018)

17 D. Hamilton, E. Arca, J. Pan, S. Siol, M. Young, S. Lany, A. Zakutayev, Electron scattering 

mechanisms in zinc tin nitride, submitted

18 E. Arca, A. Fioretti, S. Lany, A. C. Tamboli, G. Teeter, C. Melamed, J. Pan, K. N. Wood, E. 

Toberer, and A. Zakutayev. "Band Edge Positions and Their Impact on the Simulated Device 

Performance of ZnSnN2-Based Solar Cells." Invited Article - IEEE Journal of Photovoltaics 8, 

110 (2018)

19 K. Heinselman, J. Perkins, S. Lany, A. Zakutayev “New PV absorber materials in Mg-Sb-N 

system”, in preparation

20 Birkett, M., Savory, C.N., Rajpalke, M.K., Linhart, W.M., Whittles, T.J., Gibbon, J.T., Welch, 

A.W., Mitrovic, I.Z., Zakutayev, A., Scanlon, D.O. and Veal, T.D..Band gap temperaturedependence and exciton-like state in copper antimony sulphide, CuSbS2, APL Materials, 6, 

084904 (2018)

21 T. J. Whittles, T. D. Veal, C. N. Savory, A. W. Welch, F. W. de Souza Lucas, J. T. Gibbon, 

M. Birkett, R. J. Potter, D. O. Scanlon, A. Zakutayev, and V. R. Dhanak, Core Levels, Band 

Alignments, and Valence-Band States in CuSbS2 for Solar Cell Applications, ACS Appl. Mater. 

Interfaces, 9, 41916 (2017)

22 F. W. de Souza Lucas, H. Peng, S. Johnston, P. C. Dippo, S. Lany, L. H. Mascaro, A. 

Zakutayev, Characterization of defects in copper antimony disulfide, Journal of Materials 

Chemistry A 5, 21986, (2017)