Silicon germanium active layer with graded band gap and µc-Si:H buffer layer for high efficiency thin film solar cells. (December 2016)

• Record Type: Journal Article
• Authors: Pham, Duy Phong; Kim, Sangho; Park, Jinjoo; Le, AnhHuy Tuan; Cho, Jaehyun; Jung, Junhee; Iftiquar, S.M.; Yi, Junsin
• Is Part Of: Materials science in semiconductor processing. Volume 56(2016:Dec.)
• Page Start: 183
• Page End: 188
• Publication Date: 2016-12
• Subjects: Thin film silicon germanium solar cells -- Band-gap profiling -- µc-Si:H buffer layers; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2016.08.011
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: We investigated solar cells with graded band gap hydrogenated amorphous silicon germanium active layer and hydrogenated microcrystalline silicon buffer layer at the interface of intrinsic and n-type doped layer. A significantly improved, 10.4% device efficiency was observed in this type of single junction solar cell. The intrinsic type microcrystalline silicon buffer layer is thought to play dual roles in the device; as a crystalline seed-layer for growth of n-type hydrogenated microcrystalline silicon layer and helping efficient electron collection across the i/n interface. Based on these, an enhancement in cell parameters such as the open-circuit voltage (Voc ), and fill factor (FF) was observed, where the FF and Voc reaches up to 69% and 0.85 V respectively. Our investigation shows a simple way to improve device performance with narrow-gap silicon germanium active layer in solar cells in comparison to the conventionally constant band gap device structure.