The Study of Optical and Electrical Properties of a-SiC:H for Multi-junction Si Thin Film Solar Cell

2010 ◽  
Vol 1245 ◽  
Author(s):  
Jenny H. Shim ◽  
W.K. Yoon ◽  
S.T. Hwang ◽  
S.W. Ahn ◽  
H.M. Lee
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
High Efficiency ◽  
Open Circuit Voltage ◽  
Defect Density ◽  
Wide Bandgap ◽  
Open Circuit ◽  
Deposition Condition ◽  
Wide Bandgap Material ◽  
Pressure Regime

AbstractStudies have shown that wide bandgap material is required for high efficiency multi-junction solar cell applications. Here, we address proper deposition condition for high quality a-SiC:H films. In high power high pressure regime, we observed that the defect density get much lowered to the similar defect level of a-Si:H film with high H2 dilution. Single junction solar cells fabricated with the optimized condition show high open circuit voltage and low LID effect. The degradation after the LID test was only 13 % reduction of the efficiency indicating that a-SiC:H could be promising material for multi-junction solar cells.

scholarly journals Numerical Simulation Analysis of Ag Crystallite Effects on Interface of Front Metal and Silicon in the PERC Solar Cell

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 592
Author(s):  
Myeong Sang Jeong ◽  
Yonghwan Lee ◽  
Ka-Hyun Kim ◽  
Sungjin Choi ◽  
Min Gu Kang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
High Efficiency ◽  
Open Circuit Voltage ◽  
Surface Recombination ◽  
Open Circuit ◽  
Surface Recombination Velocity ◽  
Metal Interface ◽  
Ag Crystallites ◽  
Recombination Velocity

In the fabrication of crystalline silicon solar cells, the contact properties between the front metal electrode and silicon are one of the most important parameters for achieving high-efficiency, as it is an integral element in the formation of solar cell electrodes. This entails an increase in the surface recombination velocity and a drop in the open-circuit voltage of the solar cell; hence, controlling the recombination velocity at the metal-silicon interface becomes a critical factor in the process. In this study, the distribution of Ag crystallites formed on the silicon-metal interface, the surface recombination velocity in the silicon-metal interface and the resulting changes in the performance of the Passivated Emitter and Rear Contact (PERC) solar cells were analyzed by controlling the firing temperature. The Ag crystallite distribution gradually increased corresponding to a firing temperature increase from 850 ∘C to 950 ∘C. The surface recombination velocity at the silicon-metal interface increased from 353 to 599 cm/s and the open-circuit voltage of the PERC solar cell decreased from 659.7 to 647 mV. Technology Computer-Aided Design (TCAD) simulation was used for detailed analysis on the effect of the surface recombination velocity at the silicon-metal interface on the PERC solar cell performance. Simulations showed that the increase in the distribution of Ag crystallites and surface recombination velocity at the silicon-metal interface played an important role in the decrease of open-circuit voltage of the PERC solar cell at temperatures of 850–900 ∘C, whereas the damage caused by the emitter over fire was determined as the main cause of the voltage drop at 950 ∘C. These results are expected to serve as a steppingstone for further research on improvement in the silicon-metal interface properties of silicon-based solar cells and investigation on high-efficiency solar cells.

A high efficiency solution processed polymer inverted triple-junction solar cell exhibiting a power conversion efficiency of 11.83%

2015 ◽  
Vol 8 (1) ◽  
pp. 303-316 ◽  
Author(s):  
Abd. Rashid bin Mohd Yusoff ◽  
Dongcheon Kim ◽  
Hyeong Pil Kim ◽  
Fabio Kurt Shneider ◽  
Wilson Jose da Silva ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Triple Junction ◽  
High Efficiency ◽  
Open Circuit Voltage ◽  
Power Conversion ◽  
Open Circuit ◽  
Tandem Solar Cells

We propose that 1 + 1 + 1 triple-junction solar cells can provide an increased efficiency, as well as a higher open circuit voltage, compared to tandem solar cells.

High-Efficiency HIT Solar Cells for Excellent Power Generating Properties

2008 ◽  
Vol 1123 ◽  
Author(s):  
Toshihiro Kinoshita ◽  
Daisuke Ide ◽  
Yasufumi Tsunomura ◽  
Shigeharu Taira ◽  
Toshiaki Baba ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Conversion Efficiency ◽  
Production Cost ◽  
High Efficiency ◽  
Open Circuit Voltage ◽  
Short Circuit ◽  
Open Circuit ◽  
Surface Recombination Velocity ◽  
Dominant Factor

AbstractIn order to achieve the widespread use of HIT (Hetero-junction with I etero-Intrinsic T ntrinsic Thin-layer) solar cells, it is important to reduce the power generating cost. There are three main approaches for reducing this cost: raising the conversion efficiency of the HIT cell, using a thinner wafer to reduce the wafer cost, and raising the open circuit voltage to obtain a better temperature coefficient. With the first approach, we have achieved the highest conversion efficiency values of 22.3%, confirmed by AIST, in a HIT solar cell. This cell has an open circuit voltage of 0.725 V, a short circuit current density of 38.9 mA/cm2 and a fill factor of 0.791, with a cell size of 100.5 cm2. The second approach is to use thinner Si wafers. The shortage of Si feedstock and the strong requirement of a lower sales price make it necessary for solar cell manufacturers to reduce their production cost. The wafer cost is an especially dominant factor in the production cost. In order to provide low-priced, high-quality solar cells, we are trying to use thinner wafers. We obtained a conversion efficiency of 21.4% (measured by Sanyo) for a HIT solar cell with a thickness of 85μm. Even better, there was absolutely no sagging in our HIT solar cell because of its symmetrical structure. The third approach is to raise the open circuit voltage. We obtained a remarkably higher Voc of 0.739 V with the thinner cell mentioned above because of its low surface recombination velocity. The high Voc results in good temperature properties, which allow it to generate a large amount of electricity at high temperatures.

High efficiency and high open-circuit voltage quadruple-junction silicon thin film solar cells for future electronic applications

2017 ◽  
Vol 10 (5) ◽  
pp. 1134-1141 ◽  
Author(s):  
Bofei Liu ◽  
Lisha Bai ◽  
Tiantian Li ◽  
Changchun Wei ◽  
Baozhang Li ◽  
...  
Keyword(s):  
Thin Film ◽  
Solar Cells ◽  
Solar Cell ◽  
Thin Film Solar Cell ◽  
High Efficiency ◽  
Open Circuit Voltage ◽  
Open Circuit ◽  
Thin Film Solar Cells ◽  
Silicon Thin Film ◽  
Silicon Based

A highly efficient quadruple-junction silicon based thin-film solar cell with a remarkably high open-circuit voltage was demonstrated to inspire functional photoelectrical devices for environmental applications.

Correlation of Material Properties and Open-Circuit Voltage of Amorphous Silicon Based Solar Cells

2003 ◽  
Vol 762 ◽  
Author(s):  
Baojie Yan ◽  
Jeffrey Yang ◽  
Guozhen Yue ◽  
Subhendu Guha
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
Band Gap ◽  
Material Properties ◽  
Open Circuit Voltage ◽  
Defect Density ◽  
Open Circuit ◽  
Band Tail ◽  
Simulation Results

AbstractCorrelation of hydrogenated amorphous silicon (a-Si:H) alloy material properties and solar cell characteristics have been studied experimentally and by computer simulation. Simulation results show that all three solar cell parameters, short-circuit current density (Jsc), open-circuit voltage (Voc), and fill factor (FF), decrease with increased defect density. For a given intrinsic layer thickness, a larger band gap (Eg) results in a higher Voc but a lower Jsc. However, FF does not depend on band gap. This allows us to distinguish the effect of change in band gap from that in defect density on the variation in Voc. For solar cells with good interface characteristics, a linear relation FF = βVoc + γ is obtained by light soaking experiments and simulation with different defect densities. The slope β is in the range from 2 to 3 V-1 depending on cell properties and light soaking condition, and the intersect γ depends mainly on the band gap. Comparing cells made with high H2 dilution to no H2 dilution, we find that a 58 mV enhancement in Voc with H2 dilution is due to both widening of band gap and reduced defect density. Simulation results also show that a narrower valence band tail leads to a higher Voc. We did not include this effect in the analysis due to lack of available data for correlation between H2 dilution and band tail narrowing.

III-V Multi-Junction Materials and Solar Cells on Engineered SiGe/Si Substrates

2004 ◽  
Vol 836 ◽  
Author(s):  
Steven A. Ringel ◽  
Carrie L. Andre ◽  
Matthew Lueck ◽  
David Isaacson ◽  
Arthur J. Pitera ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
High Performance ◽  
High Efficiency ◽  
Defect Density ◽  
Basic Research ◽  
Open Circuit ◽  
Si Substrates ◽  
Lattice Matched ◽  
Open Circuit Voltages

ABSTRACTThe monolithic integration of high efficiency III-V compound solar cell materials and devices with lower-cost, robust and scaleable Si substrates has been a driving force in photovoltaics (PV) basic research for decades. Recent advances in controlling mismatch-induced defects that result from structural and chemical differences between III-V solar cell materials and Si using a combination of SiGe interlayers and monolayer-scale control of III-V/IV interfaces, have led to a series of fundamental advances at the material and device levels, which establish that the great potential of III-V/Si PV is within reach. These include demonstrations of GaAs epitaxial layers on Si that are anti-phase domain-free with verified dislocation densities at or below 1×106 cm−2 and negligible interface diffusion, minority carrier lifetimes for GaAs on Si in excess of 10 ns, single junction GaAs-based solar cells on Si with open circuit voltages (Voc) in excess of 980 mV, efficiencies beyond 18%, and area-independent PV characteristics up to at least 4 cm2. These advances are attributed in large part to the use of a novel “engineered Si substrate” based on compositionally-graded SiGe buffers such that a high-quality, low defect density, relaxed, “virtual” Ge substrate could be developed that can support lattice-matched III-V epitaxy and thus merge III-V technology based on the GaAs (or Ge) lattice constant with Si wafers. This paper focuses on recent results that extend this work to the first demonstration of high performance III-V dual junction solar cells on SiGe/Si. Open circuit voltages in excess of 2 V at one-sun have been obtained for the conventionally “lattice-matched” In0.49Ga0.51P/GaAs dual junction cells on inactive, engineered SiGe/Si; to our knowledge is the first demonstration of > 2V solar power generation on a Si wafer. Comparisons with identical cells on GaAs substrates reveal that the Voc on engineered Si retains more than 94% of its homoepitaxial value, and that at present both DJ/GaAs and DJ/SiGe/Si cells are similarly limited by current mismatch in these early cells, and not fundamental defect factors associated with the engineered Si substrates.

scholarly journals Anti-LID Process with a Remote Direct Heating Method Using a Half-Bridge Resonance Circuit for a PERC Solar Cell Module

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 110
Author(s):  
Soo Min Kim ◽  
Sanghoon Jung ◽  
Yoonkap Kim ◽  
Junhee Kim
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
High Efficiency ◽  
Open Circuit Voltage ◽  
Open Circuit ◽  
Heating Method ◽  
High Efficiency Solar Cells ◽  
P Type ◽  
Cell Module ◽  
Solar Cell Module

As the importance of the levelized cost of electricity (LCOE) increases in the solar cell industry, the demand for high-efficiency solar cells is rapidly increasing. Typically, p-type passivated emitter rear contact (PERC) solar cells are the most commonly used in the industry, and their efficiency is approximately 22–23%. P-type solar cells are reported to exhibit a light-induced degradation (LID) phenomenon, in which their output constantly decreases during power generation under solar radiation, and the output significantly reduces as their reference efficiency increases. Ultra-high-efficiency solar cells, which are on high demand, have a considerable output reduction due to the LID phenomenon; hence, technologies to prevent the LID phenomenon are required. However, research on this phenomenon has not been conducted because there is no method to transfer heat to solar cells inside the encapsulant when the modules are produced. In this study, a regeneration state was formed by remotely heating solar cells without damaging the encapsulant of the solar cell module. This was accomplished by using a heating method based on an induction magnetic field. A half-bridge resonance circuit was used to apply the induction magnetic field, and the temperature of the solar cell was controlled by adjusting the magnitude of the current flowing through the coil. To determine whether only the solar cell was heated, the temperature distribution inside the module was analyzed using an IR camera. The minority carrier lifetime was examined by real-time observation of the open-circuit voltage pattern of the solar cell. Finally, the observed real-time open-circuit voltage data were used, and dynamic simulation of the regeneration process was applied to analyze the LID activation energy generated in the regeneration process of the solar cell module. In conclusion, research was conducted on applying the regeneration state to prevent the LID phenomenon in the solar-cell-module stage, and the LID activation energy of the solar cell module was extracted. Based on this, a nondestructive degradation prevention technology for the solar cell module was developed.

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.

scholarly journals Efficient wide-bandgap perovskite solar cells enabled by doping a bromine-rich molecule

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Rui He ◽  
Tingting Chen ◽  
Zhipeng Xuan ◽  
Tianzhen Guo ◽  
Jincheng Luo ◽  
...  
Keyword(s):  
Solar Cells ◽  
High Performance ◽  
Open Circuit Voltage ◽  
Perovskite Solar Cells ◽  
Wide Bandgap ◽  
Open Circuit ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
Tandem Solar Cells ◽  
Carrier Lifetimes

Abstract Wide-bandgap (wide-E g , ∼1.7 eV or higher) perovskite solar cells (PSCs) have attracted extensive attention due to the great potential of fabricating high-performance perovskite-based tandem solar cells via combining with low-bandgap absorbers, which is considered promising to exceed the Shockley–Queisser efficiency limit. However, inverted wide-E g PSCs with a minimized open-circuit voltage (V oc) loss, which are more suitable to prepare all-perovskite tandem devices, are still lacking study. Here, we report a strategy of adding 1,3,5-tris (bromomethyl) benzene (TBB) into wide-E g perovskite absorber to passivate the perovskite film, leading to an enhanced average V oc. Incorporation of TBB prolongs carrier lifetimes in wide-E g perovskite due to reduction of defects in perovskites and makes a better energy level matching between perovskite absorber and electron transport layer. As a result, we achieve the power conversion efficiency of 17.12% for our inverted TBB-doped PSC with an enhanced V oc of 1.19 V, compared with that (16.14%) for the control one (1.14 V).

17.8%-efficient Amorphous Silicon Heterojunction Solar Cells on p-type Silicon Wafers

2006 ◽  
Vol 910 ◽  
Author(s):  
Qi Wang ◽  
Matt P. Page ◽  
Eugene Iwancizko ◽  
Yueqin Xu ◽  
Yanfa Yan ◽  
...  
Keyword(s):  
Solar Cells ◽  
Solar Cell ◽  
Amorphous Silicon ◽  
High Efficiency ◽  
Short Circuit ◽  
Open Circuit ◽  
Layer Growth ◽  
Surface Recombination Velocity ◽  
Back Contact ◽  
P Type

AbstractWe have achieved an independently-confirmed 17.8% conversion efficiency in a 1-cm2, p-type, float-zone silicon (FZ-Si) based heterojunction solar cell. Both the front emitter and back contact are hydrogenated amorphous silicon (a-Si:H) deposited by hot-wire chemical vapor deposition (HWCVD). This is the highest reported efficiency for a HWCVD silicon heterojunction (SHJ) solar cell. Two main improvements lead to our most recent increases in efficiency: 1) the use of textured Si wafers, and 2) the application of a-Si:H heterojunctions on both sides of the cell. Despite the use of textured c-Si to increase the short-circuit current, we were able to maintain the same 0.65 V open-circuit voltage as on flat c-Si. This is achieved by coating a-Si:H conformally on the c-Si surfaces, including covering the tips of the anisotropically-etched pyramids. A brief atomic H treatment before emitter deposition is not necessary on the textured wafers, though it was helpful in the flat wafers. It is essential to high efficiency SHJ solar cells that the emitter grows abruptly as amorphous silicon, instead of as microcrystalline or epitaxial Si. The contact on each side of the cell comprises a thin (< 5 nm) low substrate temperature (~100°C) intrinsic a-Si:H layer, followed by a doped layer. Our intrinsic layers are deposited at 0.3-1.2 nm/s. The doped emitter and back-contact layers were deposited at a higher temperature (>200°C) and grown from PH3/SiH4/H2 and B2H6/SiH4/H2 doping gas mixtures, respectively. This combination of low (intrinsic) and high (doped layer) growth temperatures was optimized by lifetime and surface recombination velocity measurements. Our rapid efficiency advance suggests that HWCVD may have advantages over plasma-enhanced (PE) CVD in fabrication of high-efficiency heterojunction c-Si cells; there is no need for process optimization to avoid plasma damage to the delicate, high-quality, Si wafers.

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