TY - JOUR
T1 - Photogeneration Quantum Yield and Character of Free Charges and Excitons in PbSe Nanorods
AU - Kulkarni, Aditya
AU - Evers, Wiel H.
AU - Van Waas, Thomas P.
AU - Siebbeles, Laurens D.A.
PY - 2020
Y1 - 2020
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85083700099&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.0c00541
DO - 10.1021/acs.jpcc.0c00541
M3 - Article
AN - SCOPUS:85083700099
SN - 1932-7447
VL - 124
SP - 7550
EP - 7557
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
IS - 13
ER -