Solar energy is one of the most used sources of renewable energy worldwide for generating electricity. Photovoltaic cells also called solar cells, and LEDs are optoelectronic devices that convert sunlight directly into electricity.
Solar cells are usually made of a semiconductor material called silicon. But these cells are expensive to produce as it takes a large amount of energy to purify the silicon
Researchers from the University of Cambridge developed a method to stabilize a promising material known as perovskite for cheap solar cells, without compromising its near-perfect performance. They used an organic material as a ‘template’ so that perovskite films can be converted into the desirable phase.
There are many different perovskites, but the most promising one is the formamidinium (FA)-based FAPbI3 crystal. This compound is thermally stable, and the energy bandgap is ideal for photovoltaic applications.
The problem with FAPbI3 is that the phase that we want is only stable at temperatures above 150 degrees Celsius. At room temperature, it transitions into another phase which is not good for photovoltaic cells.
Researchers figured out that slight structural distortion to FAPbI3 gives it stability. Co-author Satyawan Nagane used an organic molecule called Ethylenediaminetetraacetic acid (EDTA) as an additive to perovskite, which acts as a templating agent, thereby converting it into the desired phase. EDTA binds to the FAPbI3 surface and gives a structure-directing effect but does not incorporate itself into the FAPbI3 structure.
This way the desired bandgap can be achieved without adding anything extra into the material using a template and perovskite can be used as a cheaper alternative for producing solar cells and LEDs.
Reference:
Journal: Tiarnan A. S. Doherty et al. ‘Stabilized tilted-octahedra halide perovskites inhibit local formation of performance-limiting phases.’ Science (2021).
Blog by Harshita Patil
Comments