In:
Progress in Photovoltaics: Research and Applications, Wiley, Vol. 30, No. 10 ( 2022-10), p. 1238-1246
Abstract:
Polycrystalline Cu(In,Ga)Se 2 (CIGSe) thin‐film solar cells exhibit gradual onset in their external quantum efficiency ( EQE ) spectra whose shape can be affected by various CIGSe material properties. Apart from influences on the charge‐carrier collection, a broadening of the EQE onset leads to enhanced radiative losses in open‐circuit voltage ( V oc ). In the present work, Gaussian broadening of parameters describing the EQE onset of thin‐film solar cells, represented by the standard deviation, 𝜎 total , was evaluated to study the impacts of the effective band‐gap energy, the electron diffusion length, and the Ga/In gradient in the CIGSe absorber. It is shown that 𝜎 total can be disentangled into contributions of these material properties, in addition to a residual component 𝜎 residual . Effectively, 𝜎 total depends only on a contribution related to the Ga/In gradient as well as on 𝜎 residual . The present work highlights the connection of this compositional gradient, the microstructure in the polycrystalline CIGSe absorber, and the luminescence emission with the residual component 𝜎 residual . It is demonstrated that a flat band‐gap with no compositional gradient in the bulk of the CIGSe absorber is essential to obtain the lowest 𝜎 total values and thus result in lower recombination losses and gains in V oc .
Type of Medium:
Online Resource
ISSN:
1062-7995
,
1099-159X
Language:
English
Publisher:
Wiley
Publication Date:
2022
detail.hit.zdb_id:
2023295-0
Permalink