Apparent quantum efficiency effects under forward bias in MZO/CdS/CdTe solar cells. (7th September 2018)

• Record Type: Journal Article
• Authors: Yang, Shun; Fang, Xiaohui; Ma, Xiao; Wu, Lili; Zhang, Jingquan; Feng, Lianghuan
• Is Part Of: Materials research express. Volume 5:Number 11(2018)
• Publication Date: 2018-09-07
• Subjects: quantum efficiency -- apparent quantum efficiency -- solar cells -- forward bias; Materials science -- Research -- Periodicals; Materials science -- Periodicals; 620.11
• DOI: 10.1088/2053-1591/aadc18
• Languages: English
• ISSNs: 2053-1591

Abstract

Abstract: The apparent quantum efficiency measurement under forward bias can be used to analyze the window layer inter-diffusion, the photocurrent loss mechanism and the battery back-contact barrier height. In this article, quantum efficiency measurement and apparent quantum efficiency measurement under forward bias are performed on the Mgx Zn1−x O/CdS/CdTe solar cells. The results show that the introduction of MZO thin film is benefit to reduce CdS thickness which improves the short-wavelength response of quantum efficiency. The inter-diffusion occurs at the interface between CdS and CdTe, where CdS0.844 Te0.156 polycrystalline thin film possibly forms. However, there might be an obvious electron barrier at the conduction band interface between CdS0.844 Te0.156 and MZO, which reduces the carrier collection efficiency. In addition, more photo-generated carriers are collected with increasing forward bias in the space charge region of the back contact barrier to generate a current opposite to the primary photocurrent. So the AQE response for the cell without the back contact decreases monotonously in the wavelength range of 300–600 nm and has a lower negative peak in the range of 800–900 nm when the forward bias exceeds 0.6 V.