Contactless measurements of photocarrier transport properties in perovskite single crystals.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 30962444.
- Also identified by DOI 10.1038/s41467-019-09538-7 and PMC identifier 6453944.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The remarkable properties of metal halide perovskites arising from their impressive charge carrier diffusion lengths have led to rapid advances in solution-processed optoelectronics. Unfortunately, diffusion lengths reported in perovskite single crystals have ranged widely - from 3 μm to 3 mm - for ostensibly similar materials. Here we report a contactless method to measure the carrier mobility and further extract the diffusion length: our approach avoids both the effects of contact resistance and those of high electric field. We vary the density of quenchers - epitaxially included within perovskite single crystals - and report the dependence of excited state lifetime in the perovskite on inter-quencher spacing. Our results are repeatable and self-consistent (i.e. they agree on diffusion length for many different quencher concentrations) to within ± 6%. Using this method, we obtain a diffusion length in metal-halide perovskites of 2.6 μm ± 0.1 μm.