Harnessing solar power is said by researchers to require a material that not only absorbs light efficiently, but which also converts the energy to highly mobile electrical current. Looking to find this ‘ideal mix’ in a single material is a challenge, so scientists have been experimenting with ways to ‘hybrids’.
Scientists from the US Brookhaven National Laboratory, Stony Brook University and the University of Nebraska have combined the light harvesting properties of quantum dots with the tunable electrical conductivity of a layered tin disulphide semiconductor. The work is said to pave the way for the use of these materials in a range of optoelectronic applications.
According to Brookhaven chemist Mircea Cotlet: “Two dimensional metal dichalcogenides, like tin disulphide, have some promising properties for solar energy conversion and photodetector applications, including a high surface to volume aspect ratio. But no semiconducting material has it all. These materials are very thin and are poor light absorbers. So we were trying to mix them with other nanomaterials, like light absorbing quantum dots, to improve their performance through energy transfer.”
The researchers found the rate for non radiative energy transfer from individual quantum dots to tin disulphide increased with the number of tin disulphide layers. Looking to test their work, the team incorporated the hybrid material into a photo FET. According to the results, the hybrid material enhanced the performance of the photo FETs dramatically, with a photocurrent response 500% better than FETs made with tin disulphide alone.
Cotlet concluded: “The idea of ‘doping’ 2D layered materials with quantum dots to enhance their light absorbing properties shows promise for designing better solar cells and photodetectors.”
Author
Graham Pitcher
Source: www.newelectronics.co.uk