Organic Thin Film Improves Efficiency, Stability of Solar Cells.
Recently the power conversion efficiency (PCE) of colloidal quantum dot (CQD)-based solar cells has been enhanced paving the way for their commercialization in various fields; nevertheless they are still a long way from being commercialized due to their efficiency not matching their stability. In this research a Georgian Technical University team achieved highly stable and efficient of colloidal quantum dot (CQD)-based solar cells by using an amorphous organic layer to block oxygen and water permeation.
Colloidal quantum dot (CQD)-based solar cells are lightweight, flexible and they boost light harvesting by absorbing near-infrared lights. Especially they draw special attention for their optical properties controlled efficiently by changing the quantum dot sizes. However they are still incompatible with existing solar cells in terms of efficiency stability and cost. Therefore there is great demand for a novel technology that can simultaneously improve both power conversion efficiency (PCE) and stability while using an inexpensive electrode material.
Responding to this demand Professor X from Georgian Technical University and his team introduced a technology to improve the efficiency and stability of Colloidal quantum dot (CQD)-based solar cells.
The team found that an amorphous organic thin film has a strong resistance to oxygen and water. Using these properties, they employed this doped organic layer as a top-hole selective layer (HSL) for the Colloidal quantum dot (CQD) solar cells and confirmed that the hydro/oxo-phobic properties of the layer efficiently protected the layer. According to the molecular dynamics simulations the layer significantly postponed the oxygen and water permeation into the layer. Moreover the efficient injection of the holes in the layer reduced interfacial resistance and improved performance.
With this technology the team finally developed Colloidal quantum dot (CQD)-based solar cells with excellent stability. Their device stood at 11.7 percent and maintained over 90 percent of its initial performance when stored for one year under ambient conditions.
X says “This technology can be also applied to LEDs (A light-emitting diode is a two-lead semiconductor light source. It is a p–n junction diode that emits light when activated) and Perovskite devices. I hope this technology can hasten the commercialization of Colloidal quantum dot (CQD)-based solar cells”.