Highly efficient, lead-free, cost-efficient, environmentally stable perovskite photovoltaics

Ankit Choudhary, Alex Mohan, John Bace

Faculty: Haralabos Efstathiadis

Perovskite solar cells have revolutionized the field of photovoltaics. In a mere 14 years of development, power conversion efficiencies of perovskite solar cells have increased from 3.81% to a remarkable 25.6% and still have an excellent potential for further enhancement.

However, the toxicity of most used lead-based perovskite solar cells and the short lifetime of these devices due to the degradation of the active layer with oxygen and sunlight limits their commercialization. This work aims towards fabricating a highly efficient, lead-free, cost-efficient, environmentally stable perovskite solar cell with low temperature, vacuum-free processing techniques.

Our collaborators use machine learning techniques on an extensive database of previously reported perovskite solar cells to find optimum device design. Each individual layer of this design is first characterized and optimized using UV-Vis, XPS, AFM, ellipsometry, and optical microscopy for the best device performance.

These layers are then stacked in a glass/FTO/c-TiO2/Cs3Bi2I9/CuSCN/Ag structure for an n-i-p type solar cell. These devices are then measured for Voc, Jsc, fill factor, power conversion efficiency, quantum efficiency, and lifetime.

The project’s second phase is focused on synthesizing low-dimensional perovskite materials to improve the phase stability of the active layer and encapsulation of the device to prevent device degradation.