Photoluminescence and Photoconductivity to Assess Maximum Open-Circuit Voltage and Carrier Transport in Hybrid Perovskites and Other Photovoltaic Materials

Photovoltaic (PV)
device development is much more expensive and
time-consuming than the development of the absorber layer alone. This
Perspective focuses on two methods that can be used to rapidly assess
and develop PV absorber materials independent of device development.
The absorber material properties of quasi-Fermi level splitting and
carrier diffusion length under steady effective 1 Sun illumination
are indicators of a material’s ability to achieve high VOC and JSC. These
two material properties can be rapidly and simultaneously assessed
with steady-state absolute intensity photoluminescence and photoconductivity
measurements. As a result, these methods are extremely useful for
predicting the quality and stability of PV materials prior to PV device
development. Here, we summarize the methods, discuss their strengths
and weaknesses, and compare photoluminescence and photoconductivity
results with device performance for four hybrid perovskite compositions
of various bandgaps (1.35–1.82 eV), CISe, CIGSe, and CZTSe.