Beneficial Intrinsic Hole Trapping and Its Amplitude Variation in a Highly Photoluminescent Toxic-Metal-Free Quantum Dot

Swarnali Ghosh; Soumen Mukherjee; Saptarshi Mandal; Chayan K De; Sukumar Mardanya; Arijit Saha; Prasun K Mandal

doi:10.1021/acs.jpclett.2c03373

Beneficial Intrinsic Hole Trapping and Its Amplitude Variation in a Highly Photoluminescent Toxic-Metal-Free Quantum Dot

J Phys Chem Lett. 2023 Jan 12;14(1):260-266. doi: 10.1021/acs.jpclett.2c03373. Epub 2023 Jan 3.

Authors

Swarnali Ghosh, Soumen Mukherjee, Saptarshi Mandal, Chayan K De, Sukumar Mardanya, Arijit Saha, Prasun K Mandal

PMID: 36595225
DOI: 10.1021/acs.jpclett.2c03373

Abstract

Intrinsic hole trapping as well as hole detrapping have not been observed for any quantum dot (QD) or perovskite nanocrystal (PNC) system. Moreover, amplitude variation of intrinsic hole trapping (or detrapping) has not been reported at all for any QD or PNC system. However, for a CuInS₂-based core/alloy-shell (CAS) QD system, (a) both intrinsic hole trapping and detrapping have been observed and (b) very significant amplitude variations of hole trapping (∼16 to ∼42%) and hole detrapping (∼44 to 23%) have been observed. Unlike detrimental electron trapping, hole trapping has been shown to be beneficial, having a direct correlation toward increasing PLQY to 96%. Simultaneous electron and hole trapping has been shown to be quite beneficial for the CuInS₂-based CAS QD system leading to the longest ON time (∼130 s) for which a nontoxic metal-based QD remains only in the ON-state without blinking.