Unifying view of transient responses for determining lifetime and surface recombination velocity in silicon diodes and back-surface-field solar cells, with application to experimental short-circuit-current decay

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.

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Analysis of Back Surface Field (BSF) Performance in P-Type And N-Type Monocrystalline Silicon Wafer

E3S Web of Conferences ◽

10.1051/e3sconf/20184301006 ◽

2018 ◽

Vol 43 ◽

pp. 01006 ◽

Cited By ~ 3

Author(s):

Ferdiansjah ◽

Faridah ◽

Kelvian Tirtakusuma Mularso

Keyword(s):

Solar Cell ◽

Doping Level ◽

Short Circuit ◽

Surface Recombination ◽

Short Circuit Current ◽

Short Circuit Current Density ◽

Surface Recombination Velocity ◽

Back Surface ◽

Solar Cell Performance ◽

P Type

Back Surface Field (BSF) has been used as one of means to enhance solar cell performance by reducing surface recombination velocity (SRV). One of methods to produce BSF is by introducing highly doped layer on rear surface of the wafer. Depending on the type of the dopant in wafer, the BSF layer could be either p+ or n+. This research aims to compare the performance of BSF layer both in p-type and n-type wafer in order to understand the effect of BSF on both wafer types. Monociystalline silicon wafer with thickness of 300 μm. area of 1 cm2, bulk doping level NB = 1.5×1016/cm3 both for p-type wafer and n-type wafer are used. Both wafer then converted into solar cell by adding emitter layer with concentration NE =7.5×1018/cm3 both for p-type wafer and n-type wafer. Doping profile that is used for emitter layer is following complementary error function (erfc) distribution profile. BSF concentration is varied from 1×1017/cm3 to 1×1020/cm3 for each of the cell. Solar cell performance is tested under standard condition, with AM1.5G spectrum at 1000 W/m2. Its output is measured based on its open circuit voltage (Voc). short circuit current density (JSC), efficiency (η). and fill factor (FF). The result shows that the value of VOC is relatively constant along the range of BSF concentration, which is 0.694 V – 0.702 V. The same pattern is also observed in FF value which is between 0.828 – 0.831. On the other hand, value of JSC and efficiency will drop against the increase of BSF concentration. Highest JSC which is 0.033 A/cm2 and highest efficiency which is 18.6% is achieved when BSF concentration is slightly higher than bulk doping level. The best efficiency can be produced when BSF concentration is around 1×1017cm-3.. This result confirms that surface recombination velocity has been reduced due to the increase in cell’s short circuit current density and its efficiency. In general both p-type and n-type wafer will produce higher efficiency when BSF is applied. However, the increase is larger in p-type wafer than in n-type wafer. Better performance for solar cell is achieved when BSF concentration is slightly higher that bulk doping level because at very high BSF concentration the cell’s efficiency will be decreased.

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High efficiency p+-n-n+ back-surface field silicon solar cells with very large short-circuit current densities

Solar Cells ◽

10.1016/0379-6787(82)90056-4 ◽

1982 ◽

Vol 7 (3) ◽

pp. 331-336 ◽

Cited By ~ 2

Author(s):

J. Nijs ◽

J. Van Meerbergen ◽

F. D'Hoore ◽

R. Mertens ◽

R. Van Overstraeten

Keyword(s):

Solar Cells ◽

High Efficiency ◽

Short Circuit ◽

Short Circuit Current ◽

Silicon Solar Cells ◽

Back Surface ◽

Back Surface Field ◽

Surface Field ◽

Current Densities

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Optimization of Mono-Crystalline Silicon Solar Cell Devices Using PC1D Simulation

Energies ◽

10.3390/en14164986 ◽

2021 ◽

Vol 14 (16) ◽

pp. 4986

Author(s):

Gokul Sidarth Thirunavukkarasu ◽

Mehdi Seyedmahmoudian ◽

Jaideep Chandran ◽

Alex Stojcevski ◽

Maruthamuthu Subramanian ◽

...

Keyword(s):

Solar Cell ◽

Doping Concentration ◽

Surface Recombination ◽

Surface Recombination Velocity ◽

Back Surface ◽

Solar Cell Efficiency ◽

Cell Efficiency ◽

Surface Field ◽

Recombination Velocity ◽

Pc1d Simulation

Expeditious urbanization and rapid industrialization have significantly influenced the rise of energy demand globally in the past two decades. Solar energy is considered a vital energy source that addresses this demand in a cost-effective and environmentally friendly manner. Improving solar cell efficiency is considered a prerequisite to reinforcing silicon solar cells’ growth in the energy market. In this study, the influence of various parameters like the thickness of the absorber or wafer, doping concentration, bulk resistivity, lifetime, and doping levels of the emitter and back surface field, along with the surface recombination velocity (front and back) on solar cell efficiency was investigated using PC1D simulation software. Inferences from the results indicated that the bulk resistivity of 1 Ω·cm; bulk lifetime of 2 ms; emitter (n+) doping concentration of 1×1020 cm−3 and shallow back surface field doping concentration of 1×1018 cm−3; surface recombination velocity maintained in the range of 102 and 103 cm/s obtained a solar cell efficiency of 19%. The Simulation study presented in this article allows faster, simpler, and easier impact analysis of the design considerations on the Si solar cell wafer fabrications with increased performance.

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Enhanced Performance of Nanotextured Silicon Solar Cells with Excellent Light-Trapping Properties

Photonics ◽

10.3390/photonics8070272 ◽

2021 ◽

Vol 8 (7) ◽

pp. 272

Author(s):

Bingfei Dou ◽

Rui Jia ◽

Zhao Xing ◽

Xiaojiang Yao ◽

Dongping Xiao ◽

...

Keyword(s):

Solar Cells ◽

Light Trapping ◽

Short Circuit ◽

Surface Recombination ◽

Atomic Layer ◽

Short Circuit Current ◽

Open Circuit ◽

Surface Recombination Velocity ◽

Electrode Contact ◽

Recombination Velocity

Light-trapping nanostructures have been widely used for improving solar cells’ performance, but the higher surface recombination and poor electrode contact introduced need to be addressed. In this work, silicon nanostructures were synthesized via silver-catalyzed etching to texturize solar cells. Atomic-layer-deposited Al2O3 passivated the nanotextured cells. A surface recombination velocity of 126 cm/s was obtained, much lower than the 228 cm/s of the SiNX-passivated one. Additionally, the open-circuit voltage (VOC) of the nanotextured cells improved significantly from 582 to 610 mV, as did the short-circuit current (JSC) from 25.5 to 31 mA/cm2. Furthermore, the electrode contact property was enhanced by light-induced plating. A best efficiency of 13.3% for nano-textured cells was obtained, which is higher than the planar cell’s 12%.

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Numerical Investigation of Graphene as a Back Surface Field Layer on the Performance of Cadmium Telluride Solar Cell

Molecules ◽

10.3390/molecules26113275 ◽

2021 ◽

Vol 26 (11) ◽

pp. 3275

Author(s):

Devendra KC ◽

Deb Kumar Shah ◽

M. Shaheer Akhtar ◽

Mira Park ◽

Chong Yeal Kim ◽

...

Keyword(s):

Solar Cells ◽

Solar Cell ◽

Doping Concentration ◽

Carrier Lifetime ◽

Short Circuit ◽

Back Surface ◽

Back Surface Field ◽

Cdte Solar Cell ◽

Cdte Solar Cells ◽

Surface Field

This paper numerically explores the possibility of ultrathin layering and high efficiency of graphene as a back surface field (BSF) based on a CdTe solar cell by Personal computer one-dimensional (PC1D) simulation. CdTe solar cells have been characterized and studied by varying the carrier lifetime, doping concentration, thickness, and bandgap of the graphene layer. With simulation results, the highest short-circuit current (Isc = 2.09 A), power conversion efficiency (h = 15%), and quantum efficiency (QE ~ 85%) were achieved at a carrier lifetime of 1 × 103 ms and a doping concentration of 1 × 1017 cm−3 of graphene as a BSF layer-based CdTe solar cell. The thickness of the graphene BSF layer (1 mm) was proven the ultrathin, optimal, and obtainable for the fabrication of high-performance CdTe solar cells, confirming the suitability of graphene material as a BSF. This simulation confirmed that a CdTe solar cell with the proposed graphene as the BSF layer might be highly efficient with optimized parameters for fabrication.

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