Premium
Direct Correlation of Excitonics with Efficiency in a Core–Shell Quantum Dot Solar Cell
Author(s) -
Dana Jayanta,
Maiti Sourav,
Tripathi Vaidehi S.,
Ghosh Hirendra N.
Publication year - 2018
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.201705127
Subject(s) - materials science , monolayer , ultrafast laser spectroscopy , quantum dot , high resolution transmission electron microscopy , absorption (acoustics) , charge carrier , energy conversion efficiency , solar cell , shell (structure) , carrier lifetime , band gap , spectroscopy , transmission electron microscopy , luminescence , optoelectronics , nanotechnology , composite material , silicon , physics , quantum mechanics
Shell thickness dependent band‐gap engineering of quasi type II core–shell material with higher carrier cooling time, lower interfacial defect states, and longer charge carrier recombination time can be a promising candidate for both photocatalysis and solar cell. In the present investigation, colloidal CdSe@CdS core–shells with different shell thickness (2, 4 and 6 monolayer CdS) were synthesized through hot injection method and have been characterized by high resolution transmission electron microscope (HRTEM) followed by steady state absorption and luminescence techniques. Ultrafast transient absorption (TA) studies suggest longer carrier cooling, lower interfacial surface states, and slower carrier recombination time in CdSe@CdS core–shell with increasing shell thickness. By TA spectroscopy, the role of CdS shell in power conversion efficiency (PCE) has been explained in detail. The measured PCE was found to initially increase and then decrease with increasing shell thickness. Shell thickness has been optimized to maximize the efficiency after correlating the shell controlled carrier cooling and recombination with PCE values and a maximum PCE of 3.88 % was obtained with 4 monolayers of CdS shell, which is found to be 57 % higher than compared to bare CdSe QDs.