Active layer

Quantum mechanics

Voltage

Engineering

Materials science

Layer (electronics)

Band offset

Thin-film transistor

Open-circuit voltage

Computer science

Perovskite (structure)

Inorganic chemistry

Chemical engineering

Saturation (graph theory)

Band gap

Valence band

Physics

Offset (computer science)

Saturation current

Nanotechnology

Perovskite solar cell

Mathematics

Work function

Solar cell

Combinatorics

Chemistry

Programming language

Energy conversion efficiency

Optoelectronics

Halide

Superlattices and Microstructures

With a high power-conversion efficiency (PCE) of over 23%, perovskite solar cell (PSC) technology holds a viable trajectory for commercialization. Despite its attractive features, the use of lead and degradable components in the device need to be addressed. To this end, we have carried out simulation studies to explore a non-toxic and inorganic device utilizing Cs2TiBr6 as the active layer and Cu2O as the hole transport layer (HTL). We have investigated a few of the most critical areas of device physics to glean insights into possible ways of improving the performance of such a viable technology. A PCE of 14.68% (open-circuit voltage Voc of 1.10 V, short-circuit current Jsc of 25.82 mA/cm2, and fill factor FF of 51.74%) was obtained at an optimal perovskite layer thickness of 800 nm. Our investigation further reveals that with increasing perovskite thickness, as J0 (saturation current) decreases, Voc increases. By varying the radiative recombination rate, we quantitatively demonstrate an inverse relationship with PCE, and report out a PCE of 20.49% at a 100X lower than usual recombination rate. A PCE of 14.68% was obtained with an optimal work function of 5.1 eV for the metal back contact. A conduction band offset of −0.1 eV between the TiO2 electron transport layer (ETL) and the active layer and a valence band offset of −0.4 eV between the active layer and the HTL produce optimal PCE values of 14.68% and 18.97% respectively. Lastly, we demonstrate that Cs2TiBr6 is more sensitive to defect density than the device HTL and ETL by a factor of 10.

Exploring solar cell performance of inorganic Cs2TiBr6 halide double perovskite: A numerical study