Temperature Dependent Transport in Microcrystalline PIN Diodes

2000 ◽  
Vol 609 ◽  
Author(s):  
T. Brammer ◽  
H. Stiebig ◽  
A. Lambertz ◽  
W. Reetz ◽  
H. Wagner
Keyword(s):  
Solar Cells ◽  
Fill Factor ◽  
Extraction Efficiency ◽  
Chemical Vapor ◽  
Open Circuit ◽  
Microcrystalline Silicon ◽  
Temperature Dependent ◽  
Dependent Transport ◽  
Silane Concentration ◽  
Interface Effects

ABSTRACTThe optoelectronic behavior of diodes deposited by plasma enhanced chemical vapor deposition was investigated for a series of different silane concentrations in the gas phase. The purpose of this work was to correlate device characteristics with inherent properties of microcrystalline silicon by experiments and numerical simulations. Dark diode characteristics and, therefore, the open circuit voltage behavior of this series were dominated by the bulk properties of the i-layer (equilibrium carrier concentration) as shown by numerical modeling. Measurement of the solar cell output parameters as a function of the temperature showed that the fill factor of solar cells with small silane concentrations is dominated by the dark diode characteristics. This is in contrast to the temperature dependent fill factor of solar cells with large silane concentration which is limited by the extraction efficiency of the photogenerated carriers. Interface effects dominated the temperature dependent blue response. The gain in blue response increased with temperature and silane concentration by up to 200 % which revealed transport limiting material properties in the vicinity of the p/i-interface. This behavior was attributed to the nucleation region.

Microcrystalline Single-Junction and Micromorph Tandem Thin Film Silicon Solar Cells

1998 ◽  
Vol 507 ◽  
Author(s):  
J. Meier ◽  
H. Keppner ◽  
S. Dubail ◽  
U. Kroll ◽  
P. Torres ◽  
...  
Keyword(s):  
Solar Cells ◽  
Fill Factor ◽  
Open Circuit ◽  
Silicon Solar Cells ◽  
Microcrystalline Silicon ◽  
Temperature Dependent ◽  
Cell Temperature ◽  
Recombination Mechanism ◽  
Tandem Cell ◽  
Open Circuit Voltages

ABSTRACTHigher open circuit voltages of the microcrystalline silicon bottom cell have a direct impact on the efficiency of the micromorph (μc-Si:H/a-Si:H) tandem cell. In this paper it is shown that open circuit voltages over 500 mV can be achieved leading to gc-Si:H cell efficiencies of 8.5 %. The behaviour of such cells is characterised both by the illuminated and the dark I-V characteristics in function of cell temperature. Microcrystalline cells with Voc-values higher than 500 mV and micromorph tandems possess in general a lower value of the temperature coefficient of the fill factor and thus of the efficiency, when compared to c-Si. Temperature-dependent dark I-V measurements suggest that the dominant recombination mechanism in lgc-Si:H cells is different from that prevailing in a-Si:H solar cells.

Performance of μ-Si:H Solar Cells with Amorphous P-Layer

1998 ◽  
Vol 507 ◽  
Author(s):  
Frank Siebke ◽  
Shigeo Yata ◽  
Yoshihiro Hishikawa ◽  
Makoto Tanaka
Keyword(s):  
Solar Cells ◽  
Fill Factor ◽  
Open Circuit Voltage ◽  
Silicon Layer ◽  
Amorphous Layer ◽  
Open Circuit ◽  
Optimized Design ◽  
Microcrystalline Silicon ◽  
Cell Structures ◽  
Proper Design

ABSTRACTWe investigated p-i-n solar cells with microcrystalline absorber but amorphous contact layers. Fill factor and open circuit voltage depend sensitively on the p/i interface. Using an optimized design of the p/i interface, cells with fill factors up to 65% and open circuit voltages of 0.45 V were deposited on amorphous p-layers. They are comparable to cells on micro- crystalline p-layers. A further increase of the open circuit voltage was achieved by variation of the p/i interface treatment but up to now it was accompanied by a decrease of the fill factor. We attribute this effect to a thin undoped amorphous layer at the p/i interface. Under non-optimized deposition conditions an amorphous instead of a microcrystalline silicon layer is grown at the p/i interface which can be detected by Raman measurements on cell structures. While the proper design of the p/i interface is crucial for the cell performance we did not observe significant differences between cells with amorphous and microcrystalline n-layers. The results reveal that the open circuit voltage is limited by the bulk properties of the undoped microcrystalline silicon.

Temperature Dependence of Silicon-based Thin Film Solar Cells on Their Intrinsic Absorber

2007 ◽  
Vol 989 ◽  
Author(s):  
Kobsak Sriprapha ◽  
Ihsanul Afdi Yunaz ◽  
Shuichi Hiza ◽  
Kun Ho Ahn ◽  
Seung Yeop Myong ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Temperature Dependence ◽  
Chemical Vapor ◽  
Open Circuit ◽  
Silicon Solar Cells ◽  
Microcrystalline Silicon ◽  
Solar Simulator ◽  
Lower Temperature ◽  
Silicon Based

AbstractThe temperature dependence of Si-based thin-film single junction solar cells on the phase of the intrinsic absorber is investigated in order to find the optimal absorber at high operating temperatures. For comparison, hydrogenated amorphous, protocrystalline, and microcrystalline silicon solar cells are fabricated by plasma-enhanced chemical vapor deposition and hot-wired CVD techniques. Photo J-V characteristics are measured using a solar simulator at the ambient temperature range of 25-85°C. It is found that the cells with a higher open-circuit voltage usually show lower temperature-dependent behaviors; the protocrystalline silicon solar cells provide the lowest temperature coefficient of efficiency, while the microcrystalline silicon solar cells are highly sensitive to the temperature. Therefore, protocrystalline silicon solar cells are promising for use in high temperature regions.

P-layer Optimization in High Performance a-Si:H Solar Cells

2010 ◽  
Vol 1245 ◽  
Author(s):  
Yueqin Xu ◽  
Bill Nemeth ◽  
Falah Hasoon ◽  
Lusheng Hong ◽  
Anna Duda ◽  
...  
Keyword(s):  
Solar Cells ◽  
High Performance ◽  
Fill Factor ◽  
Transparent Conducting Oxide ◽  
Critical Role ◽  
Chemical Vapor ◽  
Open Circuit ◽  
Oxide Glass ◽  
Frequency Plasma ◽  
Hydrogenated Amorphous

AbstractWe report our progress toward high-performance hydrogenated amorphous silicon (a-Si:H) solar cells fabricated in NREL's newly installed multi-chamber film Si deposition system. The a-Si:H layers are made by standard radio frequency plasma-enhanced chemical vapor deposition. This system produces a-Si:H p-i-n single-junction devices on Asahi U-type transparent conducting oxide glass with >10% initial efficiency. The importance of the p-layer to the cell is identified: it plays a critical role in further improving cell performance. Our optimization process involves changing p-layer parameters such as dopant levels, bandgap, and thickness in cells as well as applying a double p-layer. With the optimized p-layer, we are able to increase the fill factor of our cells to as high as 72% while maintaining high open-circuit voltage.

Nanostructure Control of Si and Ge Quantum Dots Based Solar Cells Using Plasma Processes

2014 ◽  
Vol 783-786 ◽  
pp. 2022-2027 ◽  
Author(s):  
Masaharu Shiratani ◽  
Giichiro Uchida ◽  
Hyun Woong Seo ◽  
Daiki Ichida ◽  
Kazunori Koga ◽  
...  
Keyword(s):  
Solar Cells ◽  
Fill Factor ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Electrical Power ◽  
Chemical Vapor ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Si Nanoparticles ◽  
Sensitized Solar Cells

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.

Comparison of Prolonged Light Soaking of Single and Stacked Junction A-SI:H Solar Cells

1989 ◽  
Vol 149 ◽  
Author(s):  
P. Lechner ◽  
B. Scheppat ◽  
R. Geyer ◽  
H. Rübel ◽  
M. Gorn ◽  
...  
Keyword(s):  
Solar Cells ◽  
Layer Thickness ◽  
Fill Factor ◽  
Open Circuit Voltage ◽  
Prolonged Exposure ◽  
Single Cells ◽  
Open Circuit ◽  
Si Solar Cells ◽  
Extended Exposure ◽  
Interface Effects

ABSTRACTLight-induced degradation of a-Si solar cells is dependent on their design. The degradation rate for single cells increases with i-layer thickness. Very thin i-layer devices (d < 100 nm) exhibit a delayed onset of degradation which is accompanied by a severe loss of open circuit voltage at prolonged exposure times. By extrapolating i-layer thickness to zero and therefore separating bulk and interface effects, the latter may account for a substantial loss of stability. The introduction of a SiC buffer layer at the p/i interface results in a considerable higher degradation mainly caused by a loss in fill factor.Double stacked cells, as compared to single cells having similar initial efficiences, show higher stability. The instability at extended exposure times of very thin single cells as used in a tandem configuration did not influence the stacked device.

Correlation Between the Raman Crystallinity of p-Type Micro-Crystalline Silicon Layer and Open Circuit Voltage of n-i-p Solar Cells

2015 ◽  
Vol 15 (10) ◽  
pp. 7760-7764
Author(s):  
Junhee Jung ◽  
Sunbo Kim ◽  
Jinjoo Park ◽  
Chonghoon Shin ◽  
Duy Phong Pham ◽  
...  
Keyword(s):  
Solar Cells ◽  
Fill Factor ◽  
Open Circuit Voltage ◽  
Silicon Layer ◽  
Open Circuit ◽  
Cell Performance ◽  
Internal Electric Field ◽  
Microcrystalline Silicon ◽  
Silicon Oxide Layer ◽  
Substrate Layer

This article mainly discusses the difference between p-i-n and n-i-p type solar cells. Their structural difference has an effect on cell performance, such as open circuit voltage and fill factor. Although the deposition conditions are the same for both p-i-n and n-i-p cases, the substrate layers for depositing p-type microcrystalline silicon layers differ. In n-i-p cells, the substrate layer is p-type amorphous silicon oxide layer; whereas, in p-i-n cells, the substrate layer is ZnO:Al. The interfacial change leads to a 12% difference in the crystallinity of the p-type microcrystalline silicon layers. When the p-type microcrystalline silicon layer’s crystallinity was not sufficient to activate an internal electric field, the open circuit voltage and fill factor decreased 0.075 V and 7.36%, respectively. We analyzed this problem by comparing the Raman spectra, electrical conductivity, activation energy and solar cell performance. By adjusting the thickness of the p-type microcrystalline silicon layer, we increased the open circuit voltage of the n-i-p cell from 0.835 to 0.91 V.

Microcrystalline (Si,Ge):H Solar Cells

2003 ◽  
Vol 762 ◽  
Author(s):  
Jianhua Zhu ◽  
Vikram L. Dalal
Keyword(s):  
Solar Cells ◽  
Buffer Layer ◽  
Quantum Efficiency ◽  
Fill Factor ◽  
Open Circuit Voltage ◽  
Defect Density ◽  
Cell Structure ◽  
Open Circuit ◽  
Base Layer ◽  
Ecr Plasma

AbstractWe report on the growth and properties of microcrystalline Si:H and (Si,Ge):H solar cells on stainless steel substrates. The solar cells were grown using a remote, low pressure ECR plasma system. In order to crystallize (Si,Ge), much higher hydrogen dilution (∼40:1) had to be used compared to the case for mc-Si:H, where a dilution of 10:1 was adequate for crystallization. The solar cell structure was of the p+nn+ type, with light entering the p+ layer. It was found that it was advantageous to use a thin a-Si:H buffer layer at the back of the cells in order to reduce shunt density and improve the performance of the cells. A graded gap buffer layer was used at the p+n interface so as to improve the open-circuit voltage and fill factor. The open circuit voltage and fill factor decreased as the Ge content increased. Quantum efficiency measurements indicated that the device was indeed microcrystalline and followed the absorption characteristics of crystalline ( Si,Ge). As the Ge content increased, quantum efficiency in the infrared increased. X-ray measurements of films indicated grain sizes of ∼ 10nm. EDAX measurements were used to measure the Ge content in the films and devices. Capacitance measurements at low frequencies ( ~100 Hz and 1 kHz) indicated that the base layer was indeed behaving as a crystalline material, with classical C(V) curves. The defect density varied between 1x1016 to 2x1017/cm3, with higher defects indicated as the Ge concentration increased.

Kinetics of Light-Induced Effects in Mixed-Phase Hydrogenated Silicon Solar Cells

2003 ◽  
Vol 762 ◽  
Author(s):  
Guozhen Yuea ◽  
Baojie Yan ◽  
Jeffrey Yang ◽  
Kenneth Lord ◽  
Subhendu Guha
Keyword(s):  
Solar Cells ◽  
Fill Factor ◽  
Equivalent Circuit Model ◽  
Open Circuit ◽  
Mixed Phase ◽  
Silicon Solar Cells ◽  
Initial Increase ◽  
Soaking Time ◽  
Hydrogenated Silicon ◽  
Kinetics Of

AbstractWe have observed a significant light-induced increase in the open-circuit voltage (Voc) of mixed-phase hydrogenated silicon solar cells. In this study, we investigate the kinetics of the light-induced effects. The results show that the cells with different initial Voc have different kinetic behavior. For the cells with a low initial Voc (less than 0.8 V), the increase in Voc is slow and does not saturate for light-soaking time of up to 16 hours. For the cells with medium initial Voc (0.8 ∼ 0.95 V), the Voc increases rapidly and then saturates. Cells with high initial Voc (0.95 ∼ 0.98 V) show an initial increase in Voc, followed bya Voc decrease. All light-soaked cells exhibit a degradation in fill factor. The temperature dependence of the kinetics shows that light soaking at high temperatures causes Voc increase to saturate faster than at low temperatures. The observed results can be explained by our recently proposed two-diode equivalent-circuit model for mixed-phase solar cells.

Study of Photoelectrochemical Solar Cell Using WSe2 Crystal

2013 ◽  
Vol 665 ◽  
pp. 330-335 ◽  
Author(s):  
Ripal Parmar ◽  
Dipak Sahay ◽  
R.J. Pathak ◽  
R.K. Shah
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Fill Factor ◽  
Short Circuit ◽  
Short Circuit Current ◽  
Electrical Energy ◽  
Open Circuit ◽  
Cell Parameters ◽  
Photoelectrochemical Solar Cell ◽  
Photoelectrochemical Solar Cells

The solar cells have been used as most promising device to convert light energy into electrical energy. In this paper authors have attempted to fabricate Photoelectrochemical solar cell with semiconductor electrode using TMDCs. The Photoelectrochemical solar cells are the solar cells which convert the solar energy into electrical energy. The photoelectrochemical cells are clean and inexhaustible sources of energy. The photoelectrochemical solar cells are fabricated using WSe2crystal and electrolyte solution of 0.025M I2, 0.5M NaI, 0.5M Na2SO4. Here the WSe2crystals were grown by direct vapour transport technique. In our investigations the solar cell parameters like short circuit current (Isc) and Open circuit voltage (Voc) were measured and from that Fill factor (F.F.) and photoconversion efficiency (η) are investigated. The results obtained shows that the value of efficiency and fill factor of solar cell varies with the illumination intensities.

Sign in / Sign up

Export Citation Format

Share Document