Optimization of Rear Local Al-Contacts on High Efficiency Commercial PERC Solar Cells with Dot and Line Openings

Crystalline silicon PERCs with dot or line openings on rear surface were studied here. By measuring the minor carrier lifetimes of the PERCs with dot and line openings, passivation effects of rear surface with dot and line openings were discussed. The performance affected by dot and line openings was analyzed in detail by testing the open-circuit voltages, short-circuit current densities, fill factors, and conversion efficiencies of the PERCs. The results show that the wider space resulted in better minor carrier lifetimes on the rear surface. And the cells with a line opening space of 0.5 mm had an average of 0.22% improvement of conversion efficiency, compared with the cells with full-area Al-BSF. On the other hand, the dot opening PERCs exhibited only a conversion efficiency of 17.4%, although there had been good rear surface reflectivity. The bad Al-Si alloy layer and large hollow densities in dot Al-contacts resulted in bad performance of the PERCs with dot openings.

Download Full-text

Numerical Simulation on Effects of TCO Work Function on Performance of a-Si:H Solar Cells

Materials Science Forum ◽

10.4028/www.scientific.net/msf.966.501 ◽

2019 ◽

Vol 966 ◽

pp. 501-506

Author(s):

Ahmad Sholih ◽

Dadan Hamdani ◽

Sigit Tri Wicaksono ◽

Mas Irfan P. Hidayat ◽

Yoyok Cahyono ◽

...

Keyword(s):

Solar Cells ◽

Work Function ◽

Conversion Efficiency ◽

High Efficiency ◽

Low Cost ◽

Short Circuit ◽

Short Circuit Current ◽

Open Circuit ◽

Conducting Oxides ◽

Conversion Efficiencies

In this paper, we have investigated the effect of the work function of transparent conducting oxides (TCO) on the performance of a-Si:H p-i-n solar cells, including open circuit voltage (VOC), short circuit current (JSC), fill factor (FF) and conversion efficiency, using AFORS-HET software. The simulation has focused on two layers: front contact work function (ΦTCO-front) and back contact work function (ΦTCO-back) with various band from 4.7 eV to 5.3 eV and 4.2 eV to 4.9 eV respectively. From the simulation results, we know that the work function of TCO greatly affects the performance of solar cells such as Voc, Jsc, FF and conversion efficiency. By optimization, we arrive at results for Voc, Jsc, FF and conversion efficiencies of 0.88 V, 8.95 mA / cm2, 65% and 5.1% respectively. This result is obtained on ΦTCO-front 5.2 eV. When ΦTCO-front 5.2 eV, the value of VOC, FF and conversion efficiency has been saturated, while the value of the J sc actually begins to decrease. Furthermore, when the ΦTCO - back is 4.3 eV, we get the best results for VOC, Jsc, FF and conversion Efficiency of 0.9 V, 8.96 mA / cm2, 73 % and 5.9 % respectively. When ΦTCO-back 4.3 eV, the value of VOC, FF and conversion efficiency begins to decrease, while the value of the Jsc does’t change significantly. These optimizations may help in producing low cost high efficiency p-i-n solar cells experimentally.

Download Full-text

Over 30% efficiency bifacial 4-terminal perovskite-heterojunction silicon tandem solar cells with spectral albedo

Scientific Reports ◽

10.1038/s41598-021-94848-4 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Sangho Kim ◽

Thanh Thuy Trinh ◽

Jinjoo Park ◽

Duy Phong Pham ◽

Sunhwa Lee ◽

...

Keyword(s):

Solar Cell ◽

Conversion Efficiency ◽

Crystalline Silicon ◽

Short Circuit ◽

Solar Spectrum ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Production Costs ◽

White Sand ◽

Reflected Light

AbstractWe developed and designed a bifacial four-terminal perovskite (PVK)/crystalline silicon (c-Si) heterojunction (HJ) tandem solar cell configuration albedo reflection in which the c-Si HJ bottom sub-cell absorbs the solar spectrum from both the front and rear sides (reflected light from the background such as green grass, white sand, red brick, roofing shingle, snow, etc.). Using the albedo reflection and the subsequent short-circuit current density, the conversion efficiency of the PVK-filtered c-Si HJ bottom sub-cell was improved regardless of the PVK top sub-cell properties. This approach achieved a conversion efficiency exceeding 30%, which is higher than those of both the top and bottom sub-cells. Notably, this efficiency is also greater than the Schockley–Quiesser limit of the c-Si solar cell (approximately 29.43%). The proposed approach has the potential to lower industrial solar cell production costs in the near future.

Download Full-text

Simulation of a perovskite sandwich solar cell with the p-CZTS / p-CH3NH3PbCI3 / p-CZTS absorber layers

IOP Conference Series Earth and Environmental Science ◽

10.1088/1755-1315/877/1/012001 ◽

2021 ◽

Vol 877 (1) ◽

pp. 012001

Author(s):

Marwah S Mahmood ◽

N K Hassan

Keyword(s):

Solar Cell ◽

Conversion Efficiency ◽

Current Density ◽

Short Circuit ◽

Perovskite Solar Cells ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Open Circuit ◽

Current Voltage ◽

Cell Capacitance

Abstract Perovskite solar cells attract the attention because of their unique properties in photovoltaic cells. Numerical simulation to the structure of Perovskite on p-CZTS/p-CH3NH3PbCI3/p-CZTS absorber layers is performed by using a program solar cell capacitance simulator (SCAPS-1D), with changing absorber layer thickness. The effect of thickness p-CZTS/p-CH3NH3PbCI3/p-CZTS, layers at (3.2μm, 1.8 μm, 1.1 μm) respectively are studied. The obtained results are short circuit current density (Jsc ), open circuit voltage (V oc), fill factor (F. F) and power conversion efficiency (PCE) equal to (28 mA/cm2, 0.83 v, 60.58 % and 14.25 %) respectively at 1.1 μm thickness. Our findings revealed that the dependence of current - voltage characteristics on the thickness of the absorbing layers, an increase in the amount of short circuit current density with an increase in the thickness of the absorption layers and thus led to an increase in the conversion efficiency and improvement of the cell by increasing the thickness of the absorption layers.

Download Full-text

Analytical Study of the Electrical Output Characteristics of c-Si Solar Cells by Cut and Shading Phenomena

Energies ◽

10.3390/en11123397 ◽

2018 ◽

Vol 11 (12) ◽

pp. 3397 ◽

Cited By ~ 1

Author(s):

Jong Lim ◽

Woo Shin ◽

Hyemi Hwang ◽

Young-Chul Ju ◽

Suk Ko ◽

...

Keyword(s):

Solar Cells ◽

Solar Cell ◽

Crystalline Silicon ◽

Short Circuit ◽

Incident Light ◽

Short Circuit Current ◽

Open Circuit ◽

Si Solar Cell ◽

Si Solar Cells ◽

Electrical Output

Cut solar cells have received considerable attention recently as they can reduce electrical output degradation when the c-Si solar cells (crystalline-silicon solar cells) are shaded. Cut c-Si solar cells have a lower short-circuit current than normal solar cells and the decrease in short-circuit currents is similar to the shading effect of c-Si solar cells. However, the results of this study’s experiment show that the shadow effect of a c-Si solar cell reduces the V o c (open circuit voltage) in the c-Si solar cell but the V o c does not change when the c-Si solar cell is cut because the amount of incident light does not change. In this paper, the limitations of the electrical power analysis of the cut solar cells were identified when only photo current was considered and the analysis of the electric output of the cut c-Si solar cells was interpreted with a method different from that used in previous analyses. Electrical output was measured when the shaded and cut rates of c-Si solar cells were increased from 0% to 25, 50 and 75%, and a new theoretical model was compared with the experimental results using MATLAB.

Download Full-text

HIT Solar Cell With V2Ox Window Layer

MRS Advances ◽

10.1557/adv.2017.465 ◽

2017 ◽

Vol 2 (53) ◽

pp. 3147-3156 ◽

Cited By ~ 6

Author(s):

Erenn Ore ◽

Gehan Amaratunga ◽

Stefaan De Wolf

Keyword(s):

Solar Cell ◽

Physical Vapor Deposition ◽

Crystalline Silicon ◽

Layer Structure ◽

Short Circuit ◽

Short Circuit Current ◽

Open Circuit ◽

Window Layer ◽

Limiting Factors ◽

Vapor Deposition Technique

ABSTRACTIn the conventional crystalline silicon heterojunction solar cell with the intrinsic thin layer structure (the HIT solar cell), a p-doped thin film silicon or its alloy (pDTF-Si/A) is used as the hole collecting window layer. However, the parasitic absorbance in the pDTF-Si/A window layer, and the toxic, explosive diborane gas used for p-doping are limiting factors for achieving HIT cells with reduced processing costs and / or higher efficiencies. In this work, pDTF-Si/A is replaced by V2Ox, which is deposited by a simple physical vapor deposition technique. Due to the wide band gap of V2Ox, the HIT solar cell with the V2Ox window layer generates a higher short-circuit current density than the reference conventional HIT cell under 1 sun, and achieves an open-circuit voltage of 0.7 V. Furthermore, the charge carrier lifetime and pseudo-efficiency values of the HIT solar cell with the V2Ox window layer indicate that this cell has the potential to outperform the conventional HIT cell in terms of the power conversation efficiency under the standard test conditions.

Download Full-text

The Effect of Al-BSF on Seff and Rb in Industrialized Mono-Silicon Solar Cells

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.472-475.1846 ◽

2012 ◽

Vol 472-475 ◽

pp. 1846-1850

Author(s):

Shan Shan Dai ◽

Gao Jie Zhang ◽

Xiang Dong Luo ◽

Jing Xiao Wang ◽

Wen Jun Chen ◽

...

Keyword(s):

Solar Cells ◽

Spectral Response ◽

Short Circuit ◽

Rear Surface ◽

Surface Recombination ◽

Short Circuit Current ◽

Open Circuit ◽

Surface Recombination Velocity ◽

Silicon Solar Cells ◽

Back Surface

In this work, the effect of aluminum back surface field formed by screen printed various amount of Al paste on the effective rear surface recombination velocity (Seff) and the internal rear reflectance coeffeicient (Rb) of commercial mono-silicon solar cells was investigated. We demonstrated the effect of Seffand Rbon the performance of Al-BSF solar cells by simulating them with PC1D. The simulated results showed that the lower Seffcould get higher open circuit voltage (Voc), at the same time, the larger Rbcould get higher short-circuit current (Isc). Experimentally, we investigated the Seffand Rbthrough depositing Al paste with various amount (3.7, 5, 6, and 8 mg/cm2) for fabricating Al-BSF mono-silicon solar cells. Four group cells were characterized by light I-V, spectral response, hemispherical reflectance and scanning electron microscope (SEM) measurements. It was found that, a minimum Seffof 350 cm/s was gotten from the cells with Al paste of 8 mg/cm2, which was extracted by matching quantum efficiency (QE) from 800 nm to 1200 nm with PC1D, and a maximum Rbof 53.5% was obtained from Al paste of 5 mg/cm2by calculating at 1105 nm with PC1D. When the amount of Al paste was higher than 5mg/cm2, there were less Seffand lower Rb. On the other hand, when Al amount was 3.7mg/cm2, it was too little to form a closed BSF. Based on the SEM graphs and simulations with PC1D, a simple explaination was proposed for the experimental results.

Download Full-text

High-efficiency CIGS solar cell by optimization of doping concentration, thickness and energy band gap

Modern Physics Letters B ◽

10.1142/s0217984920500530 ◽

2019 ◽

Vol 34 (04) ◽

pp. 2050053

Author(s):

Fatemeh Ghavami ◽

Alireza Salehi

Keyword(s):

Solar Cell ◽

Band Gap ◽

High Efficiency ◽

Cell Structure ◽

Short Circuit ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Open Circuit ◽

Absorber Layer ◽

Window Layer

In this paper, the performance of copper-indium-gallium-diselenide Cu(In,Ga)Se2 solar cell, with ZnO window layer, ZnSe buffer layer, CIGS absorber layer and InGaP reflector layer was studied. The study was performed using the TCAD Silvaco simulator. The effects of grading the band gap of CIGS absorber layer, the various thicknesses and doping concentrations of different layers have been investigated. By optimizing the solar cell structure, we have obtained a maximum open circuit voltage of 0.91901 V, a short circuit current density of 39.89910 mA/cm2, a fill factor (FF) of 86.67040% and an efficiency of 31.78% which is much higher than the values for similar CIGS solar cells reported so far.

Download Full-text

Donor-Acceptor Polymer Based on Planar Structure of Alkylidene-Fluorene Derivative: Correlation of Power Conversion Efficiency among Polymer and Various Acceptor Units

Polymers ◽

10.3390/polym12122859 ◽

2020 ◽

Vol 12 (12) ◽

pp. 2859

Author(s):

Eui Jin Lee ◽

Ho Jun Song

Keyword(s):

Power Conversion Efficiency ◽

Conversion Efficiency ◽

Short Circuit ◽

Power Conversion ◽

Average Molecular Weight ◽

Coupling Reaction ◽

Short Circuit Current ◽

Open Circuit ◽

Planar Structure ◽

Quinoxaline Derivatives

This study synthesized a novel polymer, poly(alkylidene fluorene-alt-diphenylquinoxaline) (PAFDQ), based on a planar alkylidene-fluorene and a highly soluble quinoxaline derivative through the Suzuki coupling reaction. We designed a novel molecular structure based on alkylidene fluorene and quinoxaline derivatives due to compact packing property by the planar structure of alkyidene fluorene and efficient intra-molecular charge transfer by quinoxaline derivatives. The polymer was largely dissolved in organic solvents, with a number average molecular weight and polydispersity index of 13.2 kg/mol and 2.74, respectively. PAFDQ showed higher thermal stability compared with the general fluorene structure owing to its rigid alkylidene-fluorene structure. The highest occupied and lowest unoccupied molecular orbital levels of PAFDQ were −5.37 eV and −3.42 eV, respectively. According to X-ray diffraction measurements, PAFDQ exhibited the formation of an ordered lamellar structure and conventional edge-on π-stacking. The device based on PAFDQ/Y6-BO-4Cl showed the best performance in terms of short circuit current (9.86 mA/cm2), open-circuit voltage (0.76 V), fill factor (44.23%), and power conversion efficiency (3.32%). Moreover, in the PAFDQ/Y6-BO-4Cl-based film, the phase separation of donor-rich and acceptor-rich phases, and the connected dark domains, was observed.

Download Full-text

Design and modeling of an SJ infrared solar cell approaching upper limit of theoretical efficiency

International Journal of Modern Physics B ◽

10.1142/s0217979218500145 ◽

2018 ◽

Vol 32 (02) ◽

pp. 1850014 ◽

Cited By ~ 5

Author(s):

G. S. Sahoo ◽

G. P. Mishra

Keyword(s):

Solar Cell ◽

Quantum Efficiency ◽

Conversion Efficiency ◽

Internal Quantum Efficiency ◽

Spectral Response ◽

Short Circuit ◽

Cost Effective ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Open Circuit

Recent trends of photovoltaics account for the conversion efficiency limit making them more cost effective. To achieve this we have to leave the golden era of silicon cell and make a path towards III–V compound semiconductor groups to take advantages like bandgap engineering by alloying these compounds. In this work we have used a low bandgap GaSb material and designed a single junction (SJ) cell with a conversion efficiency of 32.98%. SILVACO ATLAS TCAD simulator has been used to simulate the proposed model using both Ray Tracing and Transfer Matrix Method (under 1 sun and 1000 sun of AM1.5G spectrum). A detailed analyses of photogeneration rate, spectral response, potential developed, external quantum efficiency (EQE), internal quantum efficiency (IQE), short-circuit current density (J[Formula: see text]), open-circuit voltage (V[Formula: see text]), fill factor (FF) and conversion efficiency ([Formula: see text]) are discussed. The obtained results are compared with previously reported SJ solar cell reports.

Download Full-text

PHOTOELECTRICAL PROPERTIES OF p-TYPE AND n-TYPE ELECTRICAL CONDUCTIVITY AMORPHOUS CARBON THIN FILMS FOR APPLICATION IN ECONOMICAL CARBON-BASED SOLAR CELLS

Surface Review and Letters ◽

10.1142/s0218625x05007219 ◽

2005 ◽

Vol 12 (03) ◽

pp. 343-350 ◽

Cited By ~ 3

Author(s):

M. RUSOP ◽

T. SOGA ◽

T. JIMBO

Keyword(s):

Energy Conversion ◽

Conversion Efficiency ◽

Fill Factor ◽

Short Circuit ◽

Wavelength Region ◽

Short Circuit Current ◽

Energy Conversion Efficiency ◽

Open Circuit ◽

Photon Absorption ◽

P Type

The successful deposition of boron ( B )-doped p-type ( p-C:B ) and phosphorous ( P )-doped n-type ( n-C:P ) carbon ( C ) films, and fabrication of p-C:B on silicon ( Si ) substrate ( p-C:B/n-Si ) and n-C:P/p-Si cells by the technique of pulsed laser deposition (PLD) using graphite target is reported. The cells' performances are represented in the dark I–V rectifying curve and I–V working curve under illumination when exposed to AM 1.5 illumination condition (100 mW/cm2, 25°C). The open circuit voltage (V oc ) and short circuit current density (J sc ) for p-C:B/n-Si are observed to vary from 230–250 mV and 1.5–2.2 mA/cm2, respectively, and to vary from 215–265 mV and 7.5–10.5 mA/cm2, respectively, for n-C:P/p-Si cells. The p-C:B/n-Si cell fabricated using the target with the amount of B by 3 Bwt% shows highest energy conversion efficiency, η = 0.20%, and fill factor, FF = 45%, while, the n-C:P/p-Si cell with the amount of P by 7 Pwt% shows highest energy conversion efficiency, η = 1.14%, and fill factor, FF = 41%. The quantum efficiencies (QE) of the p-C:B/n-Si and n-C:P/p-Si cells are observed to improve with Bwt% and Pwt%, respectively. The contributions of QE are suggested to be due to photon absorption by carbon layer in the lower wavelength region (below 750 nm) and Si substrates in the higher wavelength region. The dependence of B and P content on the electrical and optical properties of the deposited films, and the photovoltaic characteristics of the respective p-C:B/n-Si and n-C:P/p-Si heterojunction photovoltaic cells, are discussed.

Download Full-text