Query: Thin Film Silicon Solar Cells and   transparent electrodes

Candidate papers:

abstract: Inorganic nanomaterials can combine advantages typical for organic semiconductors, especially the fabrication by simple solution processes, and the high performance associated with inorganic semiconductors. In this work, we investigate the integration of such nanomaterials into solution processed, organic inorganic thin film solar cells and light emitting diodes. For this surface functionalized silicon quantum dots serve as active materials for light emission and absorption, spray deposited metal nanowires from silver and copper as transparent conductive electrodes.
author_names: Matthias Loch
title: Nanomaterials for hybrid organic inorganic optoelectronic devices processed from solution
year: 2019

abstract: In this work, the influence of electrodes' distance upon the properties of amorphous silicon (a Si:H) deposited by plasmaenhanced chemical vapor deposition method on both intrinsic and doped a Si:H films is investigated in terms of their electrical, optical, and structural characteristics. For this purpose, Fouriertransform infra red and secondary ion mass spectroscopy as well as photoconductance decay, spectral ellipsometry, and conductivity measurements are employed. Electrodes' distance is varied from 20 to 120mm. Regarding the passivation quality of the a Si: H film an optimum electrodes' distance of 60mm is found. In addition, electrodes' distance is detected to have a great influence on the accelerated initial growth rate, which strongly diminishes with increasing distance. Thus, electrodes' distance also determines the overall thickness of thin intrinsic a Si:H films being particularly interesting for utilization in heterojunction solar cells. With doped a Si:H films, however, electrodes' distance influences mainly the dopant concentration in the films and therewith their conductivity.
author_names: Nils Brinkmann

Angelika Gorgulla

Anja Bauer

Daniel Skorka

Gabriel Micard

Giso Hahn

Barbara Terheiden
title: In fl uence of electrodes distance upon properties of intrinsic and doped amorphous silicon fi lms for heterojunction solar cells
year: 2018

abstract: In order to reduce the solar cell price, the active layer thickness has been decreased, but this reduces the absorption of light, especially at high wavelengths. One of the ways to increase the absorption and efficiency of solar cells is to use metal nanoparticles and to benefit from the effect of surface plasmon resonance. In this paper, we have tried to increase the absorption and efficiency of the solar cell by placing the silver nanoparticles on zinc oxide (ZnO) layer in a solar cell with an activate layer of amorphous silicon (a Si) Also, compared to rectangular, triangular and semi cylindrical arrays, it is shown that silver nanoparticles will increase the efficiency further. Finally, the basic parameters of the proposed solar cell are examined.
author_names: Fatemeh Mohammad Jafari

Mohammad Reza Rakhshani

Mohammad ali Mansoori birjandi
title: Efficiency Enhancement in Thin Film Silicon Solar Cell Using the Plasmonic Properties of Metals
year: 2019

abstract: This work reports on developments in the field of wide band gap Cu2ZnXY4 (with X Sn, Si or Ge, and Y S, Se) kesterite thin film solar cells. An overview on recent developments and the current understanding of wide band gap kesterite absorber layers, alternative buffer layers, and suitable transparent back contacts is presented. Cu2ZnGe(S,Se)4 absorbers with absorber band gaps up to 1.7 eV have been successfully developed and integrated into solar cells. Combining a CdS buffer layer prepared by an optimized chemical bath deposition process with a 1.36 eV band gap absorber resulted in a record Cu2ZnGeSe4 cell efficiency of 7.6% while the highest open circuit voltage of 730 mV could be obtained for a 1.54 eV band gap absorber and a Zn(O,S) buffer layer. Employing InZnOx or TiO2 protective top layers on SnO2:In transparent back contacts yields 85 90% of the solar cell performance of reference cells (with Mo back contact) These advances show the potential as well as the challenges of wide band gap kesterites for future applications in high efficiency and low cost tandem photovoltaic devices.
author_names: Bart Vermang

Guy Brammertz

Marc Meuris

Thomas Schnabel

Erik Ahlswede

Leo Choubrac

Sylvie Harel

Christophe Cardinaud

Ludovic Arzel

Nicolas Barreau

Joop van Deelen

P J Bolt

Patrice Bras

Yi Ren

E Jaremalm

Samira Khelifi

Sheng Yang

J Lauwaert

Maria Batuk

Joke Hadermann

Xeniya Kozina

Evelyn Handick

Claudia Hartmann

Daniela Gerlach

A Matsuda

Shigenori Ueda

Toyohiro Chikyow

Roberto Felix

Yufeng Zhang

Regan G Wilks

Marcus Bar
title: Wide band gap kesterite absorbers for thin film solar cells: potential and challenges for their deployment in tandem devices
year: 2019

abstract: The application of thinner cadmium sulfide (CdS) window layer is a feasible approach to improve the performance of cadmium telluride (CdTe) thin film solar cells. However, the reduction of compactness and continuity of thinner CdS always deteriorates the device performance. In this work, transparent Al 2 O 3 films with different thicknesses, deposited by using atomic layer deposition (ALD) were utilized as buffer layers between the front electrode transparent conductive oxide (TCO) and CdS layers to solve this problem, and then, thin film solar cells with a structure of TCO/Al 2 O 3 /CdS/CdTe/BC/Ni were fabricated. The characteristics of the ALD Al 2 O 3 films were studied by UV visible transmittance spectrum, Raman spectroscopy, and atomic force microscopy (AFM) The light and dark J V performances of solar cells were also measured by specific instrumentations. The transmittance measurement conducted on the TCO/Al 2 O 3 films verified that the transmittance of TCO/Al 2 O 3 were comparable to that of single TCO layer, meaning that no extra absorption loss occurred when Al 2 O 3 buffer layers were introduced into cells. Furthermore, due to the advantages of the ALD method, the ALD Al 2 O 3 buffer layers formed an extremely continuous and uniform coverage on the substrates to effectively fill and block the tiny leakage channels in CdS/CdTe polycrystalline films and improve the characteristics of the interface between TCO and CdS. However, as the thickness of alumina increased, the negative effects of cells were gradually exposed, especially the increase of the series resistance (R s and the more serious "roll over" phenomenon. Finally, the cell conversion efficiency (e) of more than 13.0% accompanied by optimized uniformity performances was successfully achieved corresponding to the 10 nm thick ALD Al 2 O 3 thin film.
author_names: Guanggen Zeng

Xia Hao

Shengqiang Ren

Lianghuan Feng

Qionghua Wang
title: Application of ALD Al 2 O 3 in CdS/CdTe Thin Film Solar Cells
year: 2019

abstract: Thin film technology has a world wide reputation in the field of thin film deposition process and also it paves a way for innovative techniques in large scale applications. Modern thin film technology has evolved into a sophisticated way to increase the performance and esthetic value for making new functional devices. One such application is search of new materials for thin film solar cells as it provides the solution for the today's concern of energy crisis. Depending on the processing technology solar cells are of various types. Among them, silicon wafer solar cells and thin film solar cells are most promising. Thin film technology has made solar cells more feasible to be employed in terms of device design and fabrication. The efficiencies produced by these solar cells still need to be improved. For this many investigations for further improvement from CIGS (copper indium gallium selenide) solar cell to dye sensitized solar cells and perovskite solar cells. Due to toxic nature and environmental impact the use of lead in perovskite solar cells are replaced by tin or some materials which would equalize the achieved efficiency of lead. Hence the developments in search of innovative materials continue its path in thin film solar cells to develop the photovoltaic field by enhancing its efficiency.
author_names: Senthil T S

Kalaiselvi C R
title: New Materials for Thin Film Solar Cells
year: 2019

abstract: Here we report highly efficient, indium tin oxide (ITO) free polymer solar cells (PSCs) with an ultrathin copper (Cu) film(~10 nm) coated with a thin layer of poly[(9,9 bis(3' (N,N dimethylamino)propyl) 2,7 fluorene) alt 2,7 (9,9 dioctylfluorene) (PFN) as transparent electrode. Despite of its lower far field transmittance of the electrode, the obtained ITO free device based on the ultrathin Cu film can delivery higher absorption efficiency than that of the device based on ITO substrate in the long wavelength region, which can be attributed to the formation of metal resonant microcavity between the opaque back metal mirror (MoO3/Al electrode) and the transparent Cu film with high reflectance. As a result, polymer solar cells based on poly[[2,6' 4,8 di(5 ethylhexylthienyl)benzo[1,2 b;3,3 b]dithiophene][3 fluoro 2[(2 ethylhexyl)carbonyl]thieno[3,4 b]thiophenediyl] (PTB7 Th) and [6,6] phenyl C71 butyric acid methyl ester (PC71BM) blend show a high power conversion efficiency (PCE) of 8.21 comparable to that of the control device based on ITO electrode (with a PCE of 9.60% The results demonstrate that thermally evaporated Cu thin film electrode can be promising candidate to replace ITO for highly efficient PSCs, thus may open up the possibility for massive production of PSCs with low cost.
author_names: Quanbin Liang

Guoping Luo

Xiaoping Cheng

Hongbin Wu
title: Highly Efficient, ITO Free Polymer Solar Cells Using Ultrathin Copper Film as Transparent Electrode
year: 2019

abstract: In this study, p type amorphous silicon oxide (a SiOx) films are deposited using a radio frequency inductively coupled plasma chemical vapor deposition system. Effects of the CO2 gas flow rate on film properties and crystalline silicon heterojunction (HJ) solar cell performance are investigated. The experimental results show that the band gap of the a SiOx film can reach 2.1 eV at CO2 flow rate of 10 standard cubic centimeters per minute (sccm) but the conductivity of the film deteriorates. In the device simulation, the transparent conducting oxide and contact resistance are not taken into account. The electrodes are assumed to be perfectly conductive and transparent. The simulation result shows that there is a tradeoff between the increase in the band gap and the reduction in conductivity at increasing CO2 flow rate, and the balance occurs at the flow rate of six sccm, corresponding to a band gap of 1.95 eV, an oxygen content of 34% and a conductivity of 3.3 S/cm. The best simulated conversion efficiency is 25.58% with an open circuit voltage of 741 mV, a short circuit current density of 42.3 mA/cm2, and a fill factor of 0.816%
author_names: Chia-Hsun Hsu

Xiao-Ying Zhang

Hai-jun Lin

Shui-Yang Lien

Yun-Shao Cho

Chang-Sin Ye
title: Numerical Simulation of Crystalline Silicon Heterojunction Solar Cells with Different p Type a SiOx Window Layer
venue: Energies
year: 2019

abstract: Thin film solar cells are desirable due to minimal material usage, cost effective synthesis processes and a promising trend in efficiency rise. In this review paper, remarkable progresses of five major types of thin film solar cell (TFSC) including amorphous silicon (a Si) solar cell, copper indium gallium selenide (CIGS) solar cell, copper zinc tin sulfide (CZTS) solar cell, cadmium telluride (CdTe) solar cell and dye sensitized solar cell (DSSC) have been presented from their inception to the state of the art development. Cell configurations, different layers of these cells, their growth procedures, function and modification for working solar cells have also been explored. Critical issues that limit the performance of these cells as well as current scenario have also been addressed. Finally, a summary of this work has been presented as a comparative study among the five major types of TFSCs in terms of the state of the art data for structural, optical, and electrical properties, material availability, toxicity, stability and highest efficiency for helping readers decipher the major challenges for popularization and commercialization of this technology.
author_names: Abu Kowsar

Syed Farid Uddin Farhad

Mashudur Rahaman

Md Saidul Islam

Abdullah Yousuf Imam

Sumon Chandra Debnath

Munira Sultana

Md Azizul Hoque

Afrina Sharmin

Zahid Hasan Mahmood
title: Progress in Major Thin film Solar Cells: Growth Technologies, Layer Materials and Efficiencies
year: 2019

abstract: In this thesis, we present the development and characterization of novel approaches to carrier selective passivating contacts for crystalline silicon (c Si) solar cells. In our first approach, we benefit from a wide bandgap material, namely mixed phase silicon oxide (SiOX) High hydrogen dilution during the plasma enhanced chemical vapor deposition of a SiOX layer leads to the growth of vertically oriented silicon filaments embedded in a silicon oxide matrix. The resulting mixed phase material combines transparency and vertical conduction through the layer. We propose a layered contact structure starting with an ultra thin chemically grown SiOX 1.2nm) at the c Si wafer surface, followed by a phosphorus doped bilayer of the mixed phase SiOX, finishing with a nanocrystalline silicon layer that ensures contact with the metallization. With such a stack, an electron selective passivating contact with a saturation current density J0 of 5.3 fA/cm2 is achieved on n type wafers with hydrogenation, whereas on p type wafers the contact reached 5.8 fA/cm2 even without hydrogenation. The contact is analyzed in detail with respect to its structure and its change upon thermal treatment. Two different growth regions are detected: one with the vertically oriented silicon inclusions and a second one in which the silicon phases have more lateral growth. Crystallization and atomic redistribution are analyzed during in situ annealing in an electron microscope, leading to a better understanding of the change in distribution of phosphorus and oxygen as well as the nucleation sites. The influence of the annealing temperatures and dwell times as well as the initial doping concentration on the resulting in diffused region and the passivation quality is reported. We use simulations to relate the influence of these parameters on passivation to the different recombination mechanisms. From the analyzed phosphorus doping profiles, an interesting observation is reported. The chemical oxide varies in thickness and density depending on the wafer polarity as well as the base resistivity. Proof of concept cells including this novel structure demonstrate the suitability for electron selective passivating contacts at the device level with conversion efficiencies of 19.0% on planar wafers and 20.1% on textured wafers. Promisingly high short circuit current densities (JSC) of 35 mA/cm2 (40 mA/cm2) on planar (textured) with low parasitic absorption indicate its potential as a front contact in next generation solar cells. Additionally, the beneficial feature of the smooth refractive index change within the layers that leads to a low reflectance over a broad wavelength range, similar to a built in anti reflection coating, is presented. A second approach to reach highly transparent electron selective passivating contacts is
author_names: Josua A Stuckelberger
title: Transparent Passivating Contacts for Front Side Application in Crystalline Silicon Solar Cells
year: 2018