Thermal Equilibrium Processes in a-Si:H Solar Cells

1995 ◽  
Vol 377 ◽  
Author(s):  
Jae-Hee Lee ◽  
Jae-Seog Koh ◽  
Jin Jang

ABSTRACTHydrogenated amorphous silicon (a-Si:H) solar cells are prepared by plasma enhanced chemical vapor deposition (PECVD). Before quenching the solar cells, the short circuit current (Jsc), open circuit voltage (Voc), fill factor (F. F.) and conversion efficiency (η) are 17.79 mA/cm2, 0.79 V, 53.29, and 7.49 %, respectively. After thermal quenchine the solar cells from 200°C, Jsc, Voc, F. F., and η are 18.64 mA/cm2, 0.8 V, 53.79, and 8.02 %, respectively. We investigated the thermal equilibrium processes of each P, I, and N layers. Also, we obtained the dark current-voltage characteristics of a-Si:H solar cells before and after quenching. We analyze the results in terms of the change of the internal electric field in a-Si:H solar cells, caused by the shift of the Fermi level of P layer toward valence band.

2021 ◽  
Vol 5 (3) ◽  
pp. 242-250
Author(s):  
D. Sergeyev ◽  
K. Shunkeyev ◽  
B. Kuatov ◽  
N. Zhanturina

In this paper, the features of the characteristics of model thin-film solar cells based on the non-toxic multicomponent compound CuZn2AlS4 (CZAS) are considered. The main parameters (open-circuit voltage, short-circuit current, fill factor, efficiency) and characteristics (quantum efficiency, current-voltage characteristic) of thin-film solar cells based on CZAS have been determined. The minimum optimal thickness of the CZAS absorber is found (1-1.25 microns). Deterioration of the performance of solar cells with an increase in operating temperature (280-400 K) is shown. It is revealed that in the wavelength range of 390-500 nm CZAS has a high external quantum efficiency, which allows its use in designs of multi-junction solar cells designed to absorb solar radiation in the specified range. It is shown that the combination of CZAS films with a buffer layer of non-toxic ZnS increases the performance of solar cells.


2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Taweewat Krajangsang ◽  
Sorapong Inthisang ◽  
Aswin Hongsingthong ◽  
Amornrat Limmanee ◽  
Jaran Sritharathikhun ◽  
...  

Optimization of p-type hydrogenated microcrystalline silicon oxide thin films (p-μc-Si1-xOx:H) by very high frequency plasma enhanced chemical vapor deposition 40 MHz method for use as a p-layer of a-Si:H solar cells was performed. The properties of p-μc-Si1-xOx:H films were characterized by conductivity, Raman scattering spectroscopy, and spectroscopic ellipsometry. The wide optical band gap p-μc-Si1-xOx:H films were optimized by CO2/SiH4ratio and H2/SiH4dilution. Besides, the effects of wide-gap p-μc-Si1-xOx:H layer on the performance of a-Si:H solar cells with various optical band gaps of p-layer were also investigated. Furthermore, improvements of open circuit voltage, short circuit current, and performance of the solar cells by using the effective wide-gap p-μc-Si1-xOx:H were observed in this study. These results indicate that wide-gap p-μc-Si1-xOx:H is promising to use as window layer in a-Si:H solar cells.


2014 ◽  
Vol 783-786 ◽  
pp. 2022-2027 ◽  
Author(s):  
Masaharu Shiratani ◽  
Giichiro Uchida ◽  
Hyun Woong Seo ◽  
Daiki Ichida ◽  
Kazunori Koga ◽  
...  

We report characteristics of quantum dot (QD) sensitized solar cells using Si nanoparticles and Ge nanoparticles. Si nanoparticles were synthesized by multi-hollow discharge plasma chemical vapor deposition, whereas Ge nanoparticles were done by a radio frequency magnetron sputtering using Ar+H2under high pressure conditions. The electrical power generation from Si QDs and Ge QDs was confirmed. Si QD sensitized solar cells show an efficiency of 0.024%, fill factor of 0.32, short-circuit current of 0.75 mA/cm2and open-circuit voltage of 0.10 V, while Ge QD sensitized solar cells show an efficiency of 0.036%, fill factor of 0.38, short-circuit current of 0.64 mA/cm2and open-circuit voltage of 0.15 V.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Marshall L. Sweet ◽  
Joshua G. Clarke ◽  
Dmitry Pestov ◽  
Gary C. Tepper ◽  
James T. McLeskey

Hybrid solar cells (HSCs) with water soluble polythiophene sodium poly[2-(3-thienyl)-ethyloxy-4-butylsulfonate] (PTEBS) thin films produced using electrospray deposition (ESD) were fabricated, tested, and modeled and compared to devices produced using conventional spin coating. A single device structure of FTO/TiO2/PTEBS/Au was used to study the effects of ESD of the PTEBS layer on device performance. ESD was found to increase the short circuit current density (Jsc) by a factor of 2 while decreasing the open circuit voltage (Voc) by half compared to spin coated PTEBS films. Comparable efficiencies of 0.009% were achieved from both device construction types. Current-voltage curves were modeled using the characteristic solar cell equation and showed a similar increase in generated photocurrent with an increase by two orders of magnitude in the saturation current in devices from ESD films. Increases in Jsc are attributed to an increase in the interfacial contact area between the TiO2 and PTEBS layers, while decreases in Voc are attributed to incomplete film formation from ESD.


1991 ◽  
Vol 69 (3-4) ◽  
pp. 479-482 ◽  
Author(s):  
G. Papadopoulos ◽  
L. P. Boivin ◽  
N. G. Tarr

Solar cells with emitters consisting of a very thin (<20 nm) layer of silicon deposited in the polycrystalline phase overlaid with a thicker (≈100 nm) layer of recrystallized amorphous material were fabricated and characterized. Both layers were formed by low-pressure chemical vapor deposition with heavy in situ phosphorus doping. The highest temperature used in processing was 650 °C. Short-circuit current densities (Jsc) of 30 mA cm−2 combined with fill factors close to 0.8 were achieved under simulated 100 mW cm−2 AM1.5 illumination. Open-circuit voltages as high as 669 mV at 28 °C were obtained for cells formed on high-quality 0.1 Ω cm float zone substrates when Jsc was set to 32 mA cm−2.


2005 ◽  
Vol 862 ◽  
Author(s):  
Koeng Su Lim ◽  
Joong Hwan Kwak ◽  
Seong Won Kwon ◽  
Seung Yeop Myong

AbstractWe have developed highly stabilized (p-i-n)-type protocrystalline silicon (pc-Si:H) multilayer solar cells. However, the source of the superior light-induced stability of the pc-Si:H multilayer absorbers compared to conventional amorphous silicon (a-Si:H) absorbers remains unclear. Photoluminescence (PL) and Fourier transform infrared (FTIR) spectroscopy measured at room temperature produce strong evidence that nano-sized silicon grains embedded in regularly arranged highly H2-diluted sublayers suppress the photocreation of dangling bonds. To achieve a high conversion efficiency, we applied a double-layer p-type amorphous siliconcarbon alloy (p-a-Si1-xCx:H) structure to the pc-Si:H multilayer solar cells. The less pronounced initial short wavelength quantum efficiency variation as a function of bias voltage, and the wide overlap of dark current - voltage (JD-V) and short-circuit current - open-circuit voltage (Jsc-Voc) characteristics prove that the double p-a-Si1-xCx:H layer structure successfully reduces recombination at the p/i interface. Thus, we achieved a highly stabilized efficiency of 9.0 % without any back reflector.


Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1684
Author(s):  
Alessandro Romeo ◽  
Elisa Artegiani

CdTe is a very robust and chemically stable material and for this reason its related solar cell thin film photovoltaic technology is now the only thin film technology in the first 10 top producers in the world. CdTe has an optimum band gap for the Schockley-Queisser limit and could deliver very high efficiencies as single junction device of more than 32%, with an open circuit voltage of 1 V and a short circuit current density exceeding 30 mA/cm2. CdTe solar cells were introduced at the beginning of the 70s and they have been studied and implemented particularly in the last 30 years. The strong improvement in efficiency in the last 5 years was obtained by a new redesign of the CdTe solar cell device reaching a single solar cell efficiency of 22.1% and a module efficiency of 19%. In this paper we describe the fabrication process following the history of the solar cell as it was developed in the early years up to the latest development and changes. Moreover the paper also presents future possible alternative absorbers and discusses the only apparently controversial environmental impacts of this fantastic technology.


Crystals ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 726
Author(s):  
Ray-Hua Horng ◽  
Yu-Cheng Kao ◽  
Apoorva Sood ◽  
Po-Liang Liu ◽  
Wei-Cheng Wang ◽  
...  

In this study, a mechanical stacking technique has been used to bond together the GaInP/GaAs and poly-silicon (Si) solar wafers. A GaInP/GaAs/poly-Si triple-junction solar cell has mechanically stacked using a low-temperature bonding process which involves micro metal In balls on a metal line using a high-optical-transmission spin-coated glue material. Current–voltage measurements of the GaInP/GaAs/poly-Si triple-junction solar cells have carried out at room temperature both in the dark and under 1 sun with 100 mW/cm2 power density using a solar simulator. The GaInP/GaAs/poly-Si triple-junction solar cell has reached an efficiency of 24.5% with an open-circuit voltage of 2.68 V, a short-circuit current density of 12.39 mA/cm2, and a fill-factor of 73.8%. This study demonstrates a great potential for the low-temperature micro-metal-ball mechanical stacking technique to achieve high conversion efficiency for solar cells with three or more junctions.


Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4268
Author(s):  
Jessica de Wild ◽  
Gizem Birant ◽  
Guy Brammertz ◽  
Marc Meuris ◽  
Jef Poortmans ◽  
...  

Ultrathin Cu(In,Ga)Se2 (CIGS) absorber layers of 550 nm were grown on Ag/AlOx stacks. The addition of the stack resulted in solar cells with improved fill factor, open circuit voltage and short circuit current density. The efficiency was increased from 7% to almost 12%. Photoluminescence (PL) and time resolved PL were improved, which was attributed to the passivating properties of AlOx. A current increase of almost 2 mA/cm2 was measured, due to increased light scattering and surface roughness. With time of flight—secondary ion mass spectroscopy, the elemental profiles were measured. It was found that the Ag is incorporated through the whole CIGS layer. Secondary electron microscopic images of the Mo back revealed residuals of the Ag/AlOx stack, which was confirmed by energy dispersive X-ray spectroscopy measurements. It is assumed to induce the increased surface roughness and scattering properties. At the front, large stains are visible for the cells with the Ag/AlOx back contact. An ammonia sulfide etching step was therefore applied on the bare absorber improving the efficiency further to 11.7%. It shows the potential of utilizing an Ag/AlOx stack at the back to improve both electrical and optical properties of ultrathin CIGS solar cells.


2018 ◽  
Vol 9 ◽  
pp. 1802-1808 ◽  
Author(s):  
Katherine Atamanuk ◽  
Justin Luria ◽  
Bryan D Huey

The nanoscale optoelectronic properties of materials can be especially important for polycrystalline photovoltaics including many sensor and solar cell designs. For thin film solar cells such as CdTe, the open-circuit voltage and short-circuit current are especially critical performance indicators, often varying between and even within individual grains. A new method for directly mapping the open-circuit voltage leverages photo-conducting AFM, along with an additional proportional-integral-derivative feedback loop configured to maintain open-circuit conditions while scanning. Alternating with short-circuit current mapping efficiently provides complementary insight into the highly microstructurally sensitive local and ensemble photovoltaic performance. Furthermore, direct open-circuit voltage mapping is compatible with tomographic AFM, which additionally leverages gradual nanoscale milling by the AFM probe essentially for serial sectioning. The two-dimensional and three-dimensional results for CdTe solar cells during in situ illumination reveal local to mesoscale contributions to PV performance based on the order of magnitude variations in photovoltaic properties with distinct grains, at grain boundaries, and for sub-granular planar defects.


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