scholarly journals Material and solar cell research in high efficiency micromorph tandem solar cell

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.

1996 ◽  
Vol 452 ◽  
Author(s):  
H. Keppner ◽  
P. Torres ◽  
J. Meier ◽  
R. Platz ◽  
D. Fischer ◽  
...  

AbstractIn the past, microcrystalline silicon (μc-Si:H) has been successfully used as active semiconductor in entirely μc-Si:H p-i-n solar cells and a new type of tandem solar cell, called the “micromorph” cell, was introduced [1]. Micromorph cells consist of an amorphous silicon top cell and a microcrystalline bottom cell. In the paper a micromorph cell with a stable efficiency of 10.7 % (confirmed by ISE Freiburg) is reported.Among sofar existing crystalline silicon-based solar cell manufacturing techniques, the application of microcrystalline silicon is a new promising way towards implementing thin-film silicon solar cells with a low temperature deposition. Microcrystalline silicon can, indeed, be deposited at temperatures as low as 220°C; hence, the way is here open to use cheap substrates as, e.g. plastic or glass. In the present paper, the development of single and tandem cells containing microcrystalline silicon is reviewed. As stated in previous publications, microcrystalline silicon technique has at present a severe drawback that has yet to be overcome: Its deposition rate for solar-grade material is about 2Å/s; in a more recent case 4.3 Å/s [2] could be obtained. In the present paper, using suitable mixtures of silane, hydrogen and argon, deposition rates of 9.4 Å/s are presented. Thereby the dominating plasma mechanism and the basic properties of resulting layers are described in detail. A first entirely microcrystalline cell deposited at 8.7 Å/s has an efficiency of 3.15%.


2012 ◽  
Vol 1426 ◽  
pp. 45-49 ◽  
Author(s):  
M.M. de Jong ◽  
J.K. Rath ◽  
R.E.I. Schropp

ABSTRACTAs an alternative to crystalline silicon or thin film solar cells on rigid glass substrates, we aim to fabricate amorphous silicon (a-Si)/nanocrystalline silicon (nc-Si) tandem thin film solar cells on cheap flexible substrates. We have chosen polycarbonate as the superstrate and adapted the a-Si and nc-Si deposition processes for deposition at a maximum temperature of 130°. Because a-Si deposited at low temperatures has a high band gap, we were able to fabricate very thin (<1.2 μm) a-Si/nc-Si solar cells, because the high band gap of the a-Si shifts the current generation more towards the bottom cell, allowing for a much thinner (900 nm) bottom cell. The somewhat lower Jsc of the complete cell is partly compensated by a higher Vocwhich results in an initial conversion efficiency of 9.5% for the low temperature tandem solar cells on glass.


Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8199
Author(s):  
Changhyun Lee ◽  
Jiyeon Hyun ◽  
Jiyeon Nam ◽  
Seok-Hyun Jeong ◽  
Hoyoung Song ◽  
...  

Tunnel oxide passivated contact (TOPCon) solar cells are key emerging devices in the commercial silicon-solar-cell sector. It is essential to have a suitable bottom cell in perovskite/silicon tandem solar cells for commercial use, given that good candidates boost efficiency through increased voltage. This is due to low recombination loss through the use of polysilicon and tunneling oxides. Here, a thin amorphous silicon layer is proposed to reduce parasitic absorption in the near-infrared region (NIR) in TOPCon solar cells, when used as the bottom cell of a tandem solar-cell system. Lifetime measurements and optical microscopy (OM) revealed that modifying both the timing and temperature of the annealing step to crystalize amorphous silicon to polysilicon can improve solar cell performance. For tandem cell applications, absorption in the NIR was compared using a semitransparent perovskite cell as a filter. Taken together, we confirmed the positive results of thin poly-Si, and expect that this will improve the application of perovskite/silicon tandem solar cells.


2018 ◽  
Vol 11 (2) ◽  
pp. 394-406 ◽  
Author(s):  
Heping Shen ◽  
The Duong ◽  
Jun Peng ◽  
Daniel Jacobs ◽  
Nandi Wu ◽  
...  

A perovskite/CIGS tandem configuration is an attractive and viable approach to achieve an ultra-high efficiency and cost-effective all-thin-film solar cell.


2021 ◽  
Author(s):  
Atul Kumar

Abstract Kesterite CZTSxSe1−x has a band gap range from 1 to 1.5eV depending upon S/Se ration. The tandem of kieserite solar cell is proposed and simulated in SCAPS-1D for device configuration and analysis of the performance. CZTS of bandgap 1.5eV as top cell and CZTSSe of bandgap 1.1eV as bottom cell are stacked in tandem for the structure. The thickness of the two layer are optimized for matching the short circuit current JSC in the tandem. This study shines light on alternative technique of thin film multijunction for enhancing the efficiency of CZTSxSe1−x solar cells.


1996 ◽  
Vol 69 (27) ◽  
pp. 4224-4226 ◽  
Author(s):  
G. Ganguly ◽  
T. Ikeda ◽  
T. Nishimiya ◽  
K. Saitoh ◽  
M. Kondo ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jaya Madan ◽  
Karanveer Singh ◽  
Rahul Pandey

AbstractThe major losses that limit the efficiency of a single-junction solar cell are thermalization loss and transmission loss. Thus, to efficiently utilize the full solar spectrum and to mitigate these losses, tandem solar cells (TSC) have significantly impacted the photovoltaic (PV) landscape. In this context, the research on perovskite/silicon tandems is currently dominating the research community. The stability improvements of perovskite materials and mature fabrication techniques of silicon have underpinned the rapid progress of perovskite/silicon TSC. However, the low absorption coefficient and high module cost of the silicon are the tailbacks for the mass production of perovskite/silicon TSCs. Therefore, PV technology demands to explore some new materials other than Si to be used as absorber layer in the bottom cell. Thus, here in this work, to mitigate the aforementioned losses and to reduce cost, a 23.36% efficient two-terminal perovskite-PbS CQD monolithic tandem solar cell has been designed through comprehensive device simulations. Before analyzing the performance of the proposed TSC, the performance of perovskite top cells has been optimized in terms of variation in optical properties, thickness, and interface defect density under standalone conditions. Thereafter, filtered spectrum and associated integrated filtered power by the top cell at different perovskite thickness from 50 to 500 nm is obtained to conceive the presence of the top cell above the bottom cell with different perovskite thickness. The current matching by concurrently varying the thickness of both the top and bottom subcell has also been done to obtain the maximum deliverable tandem JSC for the device under consideration. The top/bottom subcell with current matched JSC of 16.68 mA cm−2/16.62 mA cm−2 showed the conversion efficiency of 14.60%/9.07% under tandem configuration with an optimized thickness of 143 nm/470 nm, where the top cell is simulated under AM1.5G spectrum, and bottom cell is exposed to the spectrum filtered by 143 nm thick top cell. Further, the voltages at equal current points are added together to generate tandem J–V characteristics. This work concludes a 23.36% efficient perovskite-PbS CQD tandem design with 1.79 V (VOC), 16.67 mA cm−2 (JSC) and 78.3% (FF). The perovskite-PbS CQD tandem device proposed in this work may pave the way for the development of high-efficiency tandem solar cells for low-cost applications.


2006 ◽  
Vol 910 ◽  
Author(s):  
Qi Wang ◽  
Matt P. Page ◽  
Eugene Iwancizko ◽  
Yueqin Xu ◽  
Yanfa Yan ◽  
...  

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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