Influence of sputtering deposition parameters on electrical and optical properties of aluminium-doped zinc oxide thin films for photovoltaic applications

Ewelina Krawczak,Alain Fave,Erwann Fourmond,Zdyb Agata,Slawomir Gulkowski

doi:10.1051/e3sconf/20172200090

Abstract

Transparent Conductive Oxides (TCOs) characterized by high visible transmittance and low electrical resistivity play an important role in photovoltaic technology. Aluminum doped zinc oxide (AZO) is one of the TCOs that can find its application in thin film solar cells (CIGS or CdTe PV technology) as well as in other microelectronic applications. In this paper some optical and electrical properties of ZnO:Al thin films deposited by RF magnetron sputtering method have been investigated. AZO layers have been deposited on the soda lime glass substrates with use of variable technological parameters such as pressure in the deposition chamber, power applied and temperature during the process. The composition of AZO films has been investigated by EDS method. Thickness and refraction index of the deposited layers in dependence on certain technological parameters of sputtering process have been determined by spectroscopic ellipsometry. The measurements of transmittance and sheet resistance were also performed.

Highlights

Transparent Conductive Oxides (TCO) films play a significant role as an transparent electrode in the optoelectronic and photovoltaic devices, especially in thin films solar cells [1,2,3,4,5,6]
The transparent conductive Al doped ZnO films were deposited onto soda lime glass (SLG) substrate using radio frequency (RF) (Radio Frequency) magnetron sputtering method
The influence of the sputtering time on the thickness of the Aluminum doped zinc oxide (AZO) films is presented in Fig. 3 for three different deposition powers: 1.5 W/cm2, 2 W/cm2, 2.5 W/cm2

Summary

Introduction

Transparent Conductive Oxides (TCO) films play a significant role as an transparent electrode in the optoelectronic and photovoltaic devices, especially in thin films solar cells [1,2,3,4,5,6]. Modified ZnO material, for example aluminum doped zinc oxide (AZO, ZnO:Al) can be a substitute of ITO in the top electrode or can be a part of double layer back contact in the thin film solar cell. Ellipsometry measurements provided information on the thickness of the films produced under different conditions of the deposition process Basing on these data the rate of growth was estimated and the influence of AZO thickness on index of refraction was studied. Resistivity of the obtained layers, determined in this work, plays an important role especially if they are meant to be applied as an electrode in thin film devices

Experimental

Results

Summary