Regular Article

How the absorber thickness influences the formation of reverse bias induced defects in CIGS solar cells

¹ TNO - Solliance, High Tech Campus 21, 5656 AE, Eindhoven, The Netherlands
² Delft University of Technology, PhotoVoltaic Materials and Devices (PVMD), Mekelweg 4, 2628 CD, Delft, The Netherlands
³ TNO Energy Transition − Solar Energy, Westerduinweg 3, 1755 LE, Petten, The Netherlands

^* e-mail: klaas.bakker@solliance.eu

Received: 15 July 2020
Received in final form: 28 September 2020
Accepted: 8 October 2020
Published online: 10 November 2020

Abstract

When a PV module is partially shaded, the shaded solar cells operate in a reverse bias condition. For Cu(In,Ga)Se₂ cells this condition can cause defects that irreversibly reduce the output of these cells and the full module. In order to design robust shade-tolerant CIGS modules details need to be known of the conditions at which these defects will be formed. In this study a large number of cells were exposed to different reverse bias conditions. By using simple statistics the probability of the occurrence of defects as a result of reverse bias at any given voltage has been determined. Based on our experiments we have found that the absorber thickness is one of the main parameters that affects the shade-tolerance: the thicker the absorber, the more shade tolerant the CIGS module will be.