Detection of Single Charge Trapping Defects in Semiconductor Particles by Evaluating Photon Antibunching in Delayed Photoluminescence.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 36893363.
- Also identified by DOI 10.1021/acs.nanolett.2c04004 and PMC identifier 10037414.
- 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
Time-resolved analysis of photon cross-correlation function <i>g</i><sup>(2)</sup>(τ) is applied to photoluminescence (PL) of individual submicrometer size MAPbI<sub>3</sub> perovskite crystals. Surprisingly, an antibunching effect in the long-living tail of PL is observed, while the prompt PL obeys the photon statistics typical for a classical emitter. We propose that antibunched photons from the PL decay tail originate from radiative recombination of detrapped charge carriers which were initially captured by a very limited number (down to one) of shallow defect states. The concentration of these trapping sites is estimated to be in the range 10<sup>13</sup>-10<sup>16</sup> cm<sup>-3</sup>. In principle, photon correlations can be also caused by highly nonlinear Auger recombination processes; however, in our case it requires unrealistically large Auger recombination coefficients. The potential of the time-resolved <i>g</i><sup>(2)</sup>(0) for unambiguous identification of charge rerecombination processes in semiconductors considering the actual number of charge carries and defects states per particle is demonstrated.