Hydrogenated amorphous silicon germanium by Hot Wire CVD as an alternative for microcrystalline silicon in tandem and triple junction solar cells. Issue 1666 (14th July 2014)

• Record Type: Journal Article
• Authors: Veldhuizen, L.W.; Kuang, Y.; Bakker, N.J.; van der Werf, C.H.M.; Yun, S.-J.; Schropp, R.E.I.
• Is Part Of: MRS proceedings. Issue 1666:(2014)
• Publication Date: 2014-07-14
• Subjects: thin film, -- photovoltaic, -- microstructure; Electrical engineering -- Congresses; Physics -- Congresses; Materials -- Research -- Congresses; Materials science -- Congresses; 620.11
• DOI: 10.1557/opl.2014.683
• Languages: English
• ISSNs: 0272-9172

Abstract

ABSTRACT: We study hydrogenated amorphous silicon germanium (a-SiGe:H) deposited by HWCVD for the use as low band gap absorber in multijunction junction solar cells. We deposited layers with Tauc optical band gaps of 1.21 to 1.56 eV and studied the hydrogen bonding with FTIR for layers that were deposited at several reaction pressures. For our reaction conditions, we found an optimal reaction pressure of 38 µbar. The material that is obtained under these conditions does not meet all device quality requirements for a-SiGe:H, which is, as we hypothesize, caused by the presence of He that is used to dilute the GeH4 source gas. We present an initial single junction n-i-p solar cell with a Tauc optical band gap of 1.45 eV and a short circuit current density of 18.7 mA/cm 2 .