scholarly journals PECVD-ONO: A New Deposited Firing Stable Rear Surface Passivation Layer System for Crystalline Silicon Solar Cells

2008 ◽  
Vol 2008 ◽  
pp. 1-10 ◽  
Author(s):  
M. Hofmann ◽  
S. Kambor ◽  
C. Schmidt ◽  
D. Grambole ◽  
J. Rentsch ◽  
...  

A novel plasma-enhanced chemical vapour deposited (PECVD) stack layer system consisting of a-SiOx:H, a-SiNx:H, and a-SiOx:H is presented for silicon solar cell rear side passivation. Surface recombination velocities below 60 cm/s (after firing) and below 30 cm/s (after forming gas anneal) were achieved. Solar cell precursors without front and rear metallisation showed implied open-circuit voltages Voc values extracted from quasi-steady-state photoconductance (QSSPC) measurements above 680 mV. Fully finished solar cells with up to 20.0% energy conversion efficiency are presented. A fit of the cell's internal quantum efficiency using software tool PC1D and a comparison to a full-area aluminium-back surface field (Al-BSF) and thermal SiO2 is shown. PECVD-ONO was found to be clearly superior to Al-BSF. A separation of recombination at the metallised and the passivated area at the solar cell's rear is presented using the equations of Fischer and Kray. Nuclear reaction analysis (NRA) has been used to evaluate the hydrogen depth profile of the passivation layer system at different stages.

2015 ◽  
Vol 37 ◽  
pp. 434 ◽  
Author(s):  
Razagh Hafezi ◽  
Soroush Karimi ◽  
Sharie Jamalzae ◽  
Masoud Jabbari

“Micromorph” tandem solar cells consisting of a microcrystalline silicon bottom cell and an amorphous silicon top cell are considered as one of the most promising new thin-film silicon solar-cell concepts. Their promise lies in the hope of simultaneously achieving high conversion efficiencies at relatively low manufacturing costs. The concept was introduced by IMT Neuchâtel, based on the VHF-GD (very high frequency glow discharge) deposition method. The key element of the micromorph cell is the hydrogenated microcrystalline silicon bottom cell that opens new perspectives for low-temperature thin-film crystalline silicon technology. This paper describes the use, within p–i–n- and n–i–p-type solar cells, of hydrogenated amorphous silicon (a-Si:H) and hydrogenated microcrystalline silicon (_c-Si:H) thin films (layers), both deposited at low temperatures (200_C) by plasma-assisted chemical vapour deposition (PECVD), from a mixture of silane and hydrogen. Optical and electrical properties of the i-layers are described. Finally, present performances and future perspectives for a high efficiency ‘micromorph’ (mc-Si:Hya-Si:H) tandem solar cells are discussed.


2020 ◽  
Vol 10 (14) ◽  
pp. 4887
Author(s):  
Qiaoqiao Bai ◽  
Hong Yang ◽  
Xiaoli Cheng ◽  
He Wang

In order to maximize performance in all conditions of use, and to model exactly the performance of solar cells, it is very important to study the recombination parameters under different injection levels. In this paper, the recombination parameters and their effect on the output performance of solar cells are investigated under different injection levels for the full-area aluminum back surface field (Al-BSF) solar cell and passivated emitter and rear cell (PERC) solar cell for the first time. It is found that the recombination parameter J01 of the diffusion region and the recombination parameter J02 of the depletion region for the PERC solar cell are smaller than those of the Al-BSF solar cell under the same injection level. A new finding is that the recombination parameter J01 of Al-BSF solar cells increases quickly with the decreasing injection level compared with PERC solar cells. Finally, the J01/J02 of Al-BSF and PERC solar cells is investigated, and the effects of J01/J02 on the electrical parameters are also analyzed for Al-BSF and PERC solar cells under different injection levels. The obtained conclusions not only clarify the relationship between the recombination parameters and injection levels, but also help to improve cell processes and accurately model daily energy production.


Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3275
Author(s):  
Devendra KC ◽  
Deb Kumar Shah ◽  
M. Shaheer Akhtar ◽  
Mira Park ◽  
Chong Yeal Kim ◽  
...  

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.


2021 ◽  
Author(s):  
Giuk Jeong ◽  
Seunghwan Ji ◽  
Ji Woon Choi ◽  
Gihun Jung ◽  
Byungha Shin

Sb2Se3, a quasi-1D structured binary chalcogenide, has great potential as a solar cell light absorber owing to its anisotropic carrier transport and benign grain boundaries when the absorber layer is...


Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3397 ◽  
Author(s):  
Jong Lim ◽  
Woo Shin ◽  
Hyemi Hwang ◽  
Young-Chul Ju ◽  
Suk Ko ◽  
...  

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.


2012 ◽  
Vol 472-475 ◽  
pp. 1846-1850
Author(s):  
Shan Shan Dai ◽  
Gao Jie Zhang ◽  
Xiang Dong Luo ◽  
Jing Xiao Wang ◽  
Wen Jun Chen ◽  
...  

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.


2004 ◽  
Vol 97-98 ◽  
pp. 109-114
Author(s):  
Juras Ulbikas ◽  
Karolis Požela ◽  
Daiva Ulbikienė

Considering optimization of the technology and production of Solar Cells an overall goal is to lower the production costs per Watt through optimization of the parameters of Solar Cell. The dominant material up to now for the majority of commercially produced solar cells is crystalline silicon (c-Si). A lot of efforts has been undertaken to increase the electrical efficiency of Si based solar cells above 20% [3-5]. Unfortunately, efficiency improvements are often reached only with the help of costly process steps and as result without possibility to use such improvements in industrial products. One of the trends in achieving higher efficiency in monocristalline Si based Solar Cells is introduction of complicated spatial structure on absorbing surface of SC. Reports indicates expectations of efficiencies as high as 24% in laboratory samples but with significant raise in costs for Spatial SC production (Fig. 1). It is clear that optimization of technological steps and parameters must be considered thinking about introduction of Spatial SC. Optimization in the case of Spatial SC must be provided by two steps: first of all we need to evaluate impact of spatial structure to physical properties of the SSC and in the next step evaluate technological possibilities for production of the SSC with optimized physical characteristics.


1970 ◽  
Vol 46 (1) ◽  
pp. 117-122 ◽  
Author(s):  
M Eusuf ◽  
M Khanam ◽  
S Khatun

In part II of this series, it was reported that the solar home system (SHS) supplied by REB in some islands of the Meghna river in the district of Narsingdi could not meet the demand of the recipients in the rainy season when the sky remained overcast with cloud. The tilt angle for all installations was 45° facing south. In this study, effects of direct and diffuse sunlight with variation of tilt angles from 0° to 45° were studied using a mono crystalline silicon cell. Pyranometer and the solar panel were kept under identical conditions. Energy absorbed by the solar panel in diffuse sunlight was found 0.55% of that received by the Pyranometer under similar conditions showing that mono crystalline silicon solar cell of the type under study was not suitable for use in SHS. Moreover, the gap between the panel and the solid surface below it has significant effects on the efficiency of the solar cell. Further similar study using different kinds of cells- mono crystalline, poly crystalline and amorphous is needed for proper designs of SHS. Optimization of the gap between the panel and the solid surface below it is important for roof-mounted and ground-mounted panels. Key words: Silicon solar cells; Tilt angle; Diffuse light; Home lighting; Monocrystaline. DOI: http://dx.doi.org/10.3329/bjsir.v46i1.8114 Bangladesh J. Sci. Ind. Res. 46(1), 117-122, 2011   


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