Photogeneration Quantum Yield and Character of Free Charges and Excitons in PbSe Nanorods

Lead selenide (PbSe) nanorods are of interest for applications in infrared LEDs, lasers, and photovoltaics due to the possibility of tuning their band gap from the far- to the near-infrared by decreasing their radius. We study the photogeneration quantum yield and properties of free charges and exci...

Full description

Saved in:
Bibliographic Details
Published in:Journal of physical chemistry. C 2020-04, Vol.124 (13), p.7550-7557
Main Authors: Kulkarni, Aditya, Evers, Wiel H, van Waas, Thomas P, Siebbeles, Laurens D. A
Format: Article
Language:English
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Lead selenide (PbSe) nanorods are of interest for applications in infrared LEDs, lasers, and photovoltaics due to the possibility of tuning their band gap from the far- to the near-infrared by decreasing their radius. We study the photogeneration quantum yield and properties of free charges and excitons in PbSe nanorods using a combination of time-resolved transient optical absorption and terahertz spectroscopy. Photoexcitation predominantly leads to the formation of excitons and to a smaller extent to free mobile charges. Theoretical analysis of the exprimental data yields an exciton polarizability of 10–35 C m2 V–1. The sum of the mobilities of a free electron and a hole is found to be close to 100 cm2 V–1 s–1. The high quantum yield of excitons makes PbSe nanorods of interest as a gain material in near-infrared LEDs or lasers. To use PbSe nanorods in photovoltaics, heterojunctions must be realized so that excitons can dissociate into free charges.
ISSN:1932-7447
1932-7455
DOI:10.1021/acs.jpcc.0c00541