화학공학소재연구정보센터
Electrochimica Acta, Vol.220, 176-183, 2016
Photo-assisted electrodeposition of a ZnO front contact on a p/n junction
Electrodeposition is an atmospheric and low temperature technique and consequently one of the most interesting way to grow transparent conductive materials at low cost. In this paper the electrodeposition of ZnO films as front contact of a Cu(In,Ga)(Se,S)(2) based solar cell is investigated. The electrodeposited ZnO can reach suitable conductivity and transparency for this application. One of the main challenges is to optimize its growth on the p-n junction formed by the Cu(ln,Ga)(Se,S)(2)/CdS stack. Indeed, due to the blocking behavior of this diode in dark conditions, the electrodeposition has to be photo-assisted with an appropriate incident flux. Moreover the growth of a compact film is tricky because of the poor nucleation of ZnO on the CdS surface. As this type of morphology is needed to ensure a sufficient lateral conductivity, we have adapted the electrochemical parameters in order to create a seed layer and improve the density of the nuclei in the first steps of the growth. As a result, with optimized parameters, a contact layer showing a high compactness is reproducibly deposited, leading to a 14.7% efficiency for a Cu(ln,Ga)(Se,S)2 based solar cell terminated with an electrodeposited front contact, which is close to the efficiency of the corresponding reference cell with a magnetron sputtered front electrode. (C) 2016 Elsevier Ltd. All rights reserved.