Space-charge-limited
current (SCLC) measurements have been widely
used to study the charge carrier mobility and trap density in semiconductors.
However, their applicability to metal halide perovskites is not straightforward,
due to the mixed ionic and electronic nature of these materials. Here,
we discuss the pitfalls of SCLC for perovskite semiconductors, and
especially the effect of mobile ions. We show, using drift-diffusion
(DD) simulations, that the ions strongly affect the measurement and
that the usual analysis and interpretation of SCLC need to be refined.
We highlight that the trap density and mobility cannot be directly
quantified using classical methods. We discuss the advantages of pulsed
SCLC for obtaining reliable data with minimal influence of the ionic
motion. We then show that fitting the pulsed SCLC with DD modeling
is a reliable method for extracting mobility, trap, and ion densities
simultaneously. As a proof of concept, we obtain a trap density of
1.3 × 10
13
cm
–3
, an ion density
of 1.1 × 10
13
cm
–3
, and a mobility
of 13 cm
2
V
–1
s
–1
for
a MAPbBr
3
single crystal.
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