Query: amorphous polycrystalline solar panel spectral response

title: Quantum Confinement in the Spectral Response of n Doped Germanium Quantum Dots Embedded in an Amorphous Si Layer for Quantum Dot Based Solar Cells
abstract: Quantum dot solar cells are based on the concept of harvesting different parts of the solar light spectrum with a single, cheap semiconductor by simply changing the size of the nanoparticles. Of th.

title: Spectral response and diffusion length studies of amorphous, polycrystalline, ribbon, epitaxial, and single crystal silicon MIS solar cells
abstract: Spectral response and diffusion length characteristics of the various MIS cells developed at Rutgers and previously reported in the literature have been investigated. The cells, designated according to the type of Si substrate used, appear in the following descending order based on the above studies: (1) Monsanto single crystal Si with a peak quantum efficiency (QE) of 87.4% and a diffusion length (Ln) of 70 mm, (2) Wacker polycrystalline Si, peak QE=82.8% Ln=60 mm, (3) IBM ribbon Si, (4) epitaxial Si, (5) Mobil Tyco EFG ribbon Si, and (6) amorphous Si (Plasma Physics Corp. Theoretical plots of quantum efficiency and short circuit current density are shown to be in reasonable agreement with experimental results. The enhanced ultraviolet response of the MIS cell compared to that of a commercial N/P junction cell is demonstrated even though the latter device has a peak QE of almost 100% and an Ln value of 184 mm. The spectral studies lend support to the conclusions derived from the previously measured el.

title: Spectral Response Optimization of Polycrystalline Black Silicon Solar Cell by Reactive Ion Etching Combined with PERC Technology
abstract: Reactive ion etching technology was combined with passivated emitter rear cell technology to reduce the reflectance and transmittance of incident light and improve the spectral response of polycrystalline silicon solar cell. Preconditioning with acid solution can induce the formation of worm like structures on the front surface, which could bring about the reduction of reflectance and enhancement of spectral response in the visible range. Optimization of the capping layer thickness on the rear side can enhance the internal reflection, which will decrease the transmittance and promote the spectral response in long wavelength range.

title: Interfacial spectral response under voltage and light bias to analyse low voltage in amorphous crystalline silicon heterojunction solar cell with S shape characteristics
abstract: The heterojunction silicon solar cells displaying two different open circuit voltages and having S shape light current density voltage characteristics are analyzed by observing change in quantum efficiency (QE) with voltage and light bias conditions. With forward bias voltage close to (and beyond) the S shape region, the QE is reduced uniformly in all the regions, due to dominance of barrier over junction field for collection of holes. Under white light bias along with the voltage biasing close to the S shape characteristics, an improvement of QE is observed due to saturation of defects at the interface and enhancement of photoconductivity of the amorphous Si layers. The cell with small open circuit voltage showed considerable improvement in QE from interfacial region (e.g. in the short and long wavelength region) while response in the bulk region (intermediate wavelength region) remains flat.

title: Relating photovoltaic output and spectral response of amorphous, polycrystalline, ribbon, epitaxial and single crystal MIS solar cells
abstract: Spectral response and diffusion length characteristics of the various MIS cells developed at Rutgers and previously reported in the literature have been investigated. The cells, designated according to the type of Si substrate used, appear in the following descending order based on the above studies: (1) Monsanto single crystal Si with a peak quantum efficiency (Q.E. of 87.4% and a diffusion length (Ln) of 70 um, (2) Wacker polycrystalline Si, peak Q.E. 82.8% Ln= 60 um, (3) IBM ribbon Si, (4) Epitaxial Si, (5) Mobil Tyco EFG ribbon Si and (6) amorphous Si. The Q.E. of the Monsanto Si base line cell is shown to be adequately explained in terms of the wavelength dependence of the collection efficiency and the transmittance of the barrier metal. Good agreement is also shown between theoretical and experimental plots of short circuit current density (Jsc) versus Ln. The Wacker cell shows best short wavelength response of all the cells studied including a commercial p n cell having a peak Q.E. of 100% and Ln= 184 um.

title: The Photovoltaic Cells Spectral Response and Photocurrent Seasonal Variations
abstract: The seasonal variations of solar photovoltaic cells photocurrent under cloudless conditions are analyzed. This analysis is done by using models of the absorption of solar radiation in the atmosphere and the spectral response of various types of solar cells. The problems of determining the atmospheric model parameters for calculating seasonal variations in absorption are indicated. A simple model that describes the effects of degradation and regeneration of photosensitive material is proposed to describe peculiarities of seasonal variations in the photocurrent of amorphous silicon cells.

title: High performance high temperature solar blind photodetector based on polycrystalline Ga2O3 film
abstract: In this paper, high temperature solar blind photodetectors were fabricated based on polycrystalline Ga2O3 (poly Ga2O3) film which was prepared by annealing amorphous Ga2O3 (a Ga2O3) film in oxygen atmosphere. The effects of annealing temperature on the properties of the material and the performances of the corresponding Metal semiconductor metal photodetector were investigated. The main factors affecting device performance are attributed to the oxygen vacancy defect concentration in Ga2O3 and the effective Schottky barrier height and width between gold and Ga2O3. We found that the detector based on 650 degC annealed poly Ga2O3 showed the best solar blind detection photoelectric performance and good thermal stability. More interestingly, the device has fast response recovery speed (0.16 s) low dark current =0.1 nA) and high photo to dark current ratio =97) at 200 degC high temperature operation. These performances are even better than the reported high temperature photodetectors based on high quality crystal Ga2O3 thin film or Ga2O3 bulk. Besides, our method that avoid direct high temperature growth of poly Ga2O3 and may be beneficial to its commercial large area production and further cost reduction.

title: Development of a very fast spectral response measurement system for analysis of hydrogenated amorphous silicon solar cells and modules
abstract: An important requirement for a very fast spectral response measurement system is the simultaneous illumination of the solar cell at multiple well defined wavelengths. Nowadays this can be done by means of light emitting diodes (LEDs) available for a multitude of wavelengths. For the purpose to measure the spectral response (SR) of amorphous silicon solar cells a detailed characterization of LEDs emitting in the wavelength range from 300 nm to 800 nm was performed. In the here developed equipment the LED illumination is modulated in the frequency range from 100 Hz to 200 Hz and the current generated by each LED is analyzed by a Fast Fourier Transform (FFT) to determine the current component corresponding to each wavelength. The equipment provides a signal to noise ratio of 2 4 orders of magnitude for individual wavelengths resulting in a precise measurement of the SR over the whole wavelength range. The difference of the short circuit current determined from the SR is less than 1% in comparison to a conventional system with monochromator.

title: Phase dependent radiation hardness and performance analysis of amorphous and polycrystalline Ga2O3 solar blind photodetector against swift heavy ion irradiation
abstract: Solar blind photodetectors are critically important for civil and military applications. Several of these applications, such as space exploration and nuclear energy infrastructure, demand the use of a photodetector under extreme environments. In this paper, we have studied the radiation hardness and device performance of amorphous and polycrystalline gallium oxide thin films against heavy ion (Ag7+ irradiation with a high energy of 100 MeV. Gallium oxide thin films show great tenacity against massive and highly energetic ions. The amorphous and polycrystalline phases undergo structural and morphological changes that initially induce degradation in the device performance. Nano pore like structures are formed in the amorphous film, while the polycrystalline film shows the destruction of large crystallites. The responsivity of the photodetector device reduces fourfold in the amorphous phase; however, a sixfold reduction in the performance is observed in the polycrystalline phase of the gallium oxide photodetector. The degradation is attributed to the annealing of pre existing optical defects that are otherwise responsible for the huge photoconductive gain in the detector and confirmed by photoluminescence studies. The effect of self annealing at room temperature and annealing at moderate temperature is investigated to recover the irradiated photodetector devices. Partial recovery in the polycrystalline based photodetector and two orders of magnitude enhanced responsivity and an almost twice faster response time compared to the control photodetectors in the amorphous phase are observed. This work investigates the effect of heavy and energetic ions on the performance of gallium oxide based solar blind photodetector and provides the guideline to use high energy irradiation as a tool for defect engineering.

title: Enhanced spectral response by silicon nitride index matching layer in amorphous silicon thin film solar cells
abstract: We employed the low temperature hydrogenated amorphous silicon nitride (a SiN x :H) prepared by plasma enhanced chemical vapor deposition as a refractive index n matching layers in a silicon based thin film solar cell between glass n 1.5) and the transparent conducting oxide n 2) By varying the stoichiometry, refractive index and thickness of the a SiN x :H layers, we enhanced the spectral response and efficiency of the hydrogenated amorphous silicon thin film solar cells. The refractive index of a SiN x :H was reduced from 2.32 to 1.78. Optimizing the a SiN x :H thickness to 80 nm increased the J SC from 8.3 to 9.8 mA/cm 2 and the corresponding cell efficiency increased from 4.5 to 5.3% as compared to the cell without the a SiN x :H index matching layer on planar substrate. The a SiN x :H layers with graded refractive indices were effective for enhancing the cell performance.