Rear contact SiGe solar cell with SiC passivated front surface for >90-percent external quantum efficiency and improved power conversion efficiency. (October 2016)

• Record Type: Journal Article
• Authors: Pandey, Rahul; Chaujar, Rishu
• Is Part Of: Solar energy. Volume 135(2016)
• Page Start: 242
• Page End: 252
• Publication Date: 2016-10
• Subjects: ATLAS -- Rear contact -- Power conversion efficiency -- Recombination -- SiGe -- Solar cell; Solar energy -- Periodicals; Solar engines -- Periodicals; 621.47
• DOI: 10.1016/j.solener.2016.05.056
• Languages: English
• ISSNs: 0038-092X

Abstract

Highlights: Innovative SiC-based rear contact SiGe Solar cell has been designed and simulated. EQE > 90% has been achieved in 400–650 nm wavelength spectrum. PCE of 15.4% has been achieved in 10 μm thick rear contact SiGe solar cell. Result reveals, remarkably lower surface recombination and higher optical coupling. The device has also been analyzed for concentrator photovoltaics (CPV) applications. Abstract: In this effort, 10 μm thick rear contact (RC) silicon–germanium (SiGe) based solar cell device has been discussed with SiC (20 nm)-based front surface passivation for the suppression of interface recombination as well as improvement of short circuit current density ( J SC ) and open-circuit voltage ( V OC ). The design principles presented here balance the electronic and photonic effects together and is a significant step to design highly efficient thin solar cells. Photo reflectance is significantly reduced in the UV/visible spectral region due to the presence of SiC. This results in external quantum efficiency (EQE) >90% in the spectrum range of 400–650 nm wavelength. Also, at wavelengths equivalent to 300 nm, SiC passivated device shows record EQE of 85%. The presence of SiC as a surface passivating layer shows enhanced surface characteristics in terms of reduced surface recombination and higher photon absorption rate. This results in 15.4% power conversion efficiency (PCE) under standard air mass 1.5 illuminations. Further, the proposed device has also been analyzed for concentrator photovoltaics (CPV) applications, resulting in 18.4% and 19.3% efficiencies at 1 W/cm 2 (10 suns, 27 °C) and 2 W/cm 2 (20 suns, 27 °C) respectively. Till date, the proposed design proves to be highly efficient in the sub 10 μm regime. All the simulations have been done using DEVEDIT and ATLAS device simulator