Light management design in ultra-thin chalcopyrite photovoltaic devices by employing optical modelling
article
In ultra-thin chalcopyrite solar cells and photovoltaic modules, efficient light management is required to increase the photocurrent and to gain in conversion efficiency. In this work we employ optical modelling to investigate different optical approaches and quantify their potential improvements in the short-circuit current density of Cu(In, Ga)Se 2 (CIGS)devices. For structures with an ultra-thin (500 nm)CIGS absorber, we study the improvements related to the introduction of (i)highly reflective metal back reflectors, (ii)internal nano-textures applied to the substrate and (iii)external micro-textures by using a light management foil. In the analysis we use CIGS devices in a PV module configuration, thus, solar cell structure including encapsulation and front glass. A thin Al 2 O 3 layer was considered in the structure at the rear side of CIGS for passivation and diffusion barrier for metal reflectors. We show that not any individual aforementioned approach is sufficient to compensate for the short circuit drop related to ultra-thin absorber, but a combination of a highly reflective back contact and textures (internal or external)is needed to obtain and also exceed the short-circuit current density of a thick (1800 nm)CIGS absorber.
TNO Identifier
867350
ISSN
9270248
Source
Solar Energy Materials and Solar Cells, 200, pp. 109933.
Publisher
Elsevier
Article nr.
109933
Collation
9 p.
Place of publication
Amsterdam
Pages
109933
Files
To receive the publication files, please send an e-mail request to TNO Repository.