Intense Pulsed Light Annealing of Perovskite Solar Cells

Perovskite solar cells have produced significant interest in the scientific community. In the past 6 years, the perovskite solar cell has increased in efficiency from 3.8% to a staggering 20.1%. To add to the intrigue, the perovskite solar cell uses common low cost materials such as lead or tin and does not require the large manufacturing costs of using high temperatures and vacuum systems. Despite these advantages, the perovskite solar cell is still limited in efficiency due to the smaller crystal size of the perovskite material. The smaller crystal size of the perovskite material creates a more porous material with more grain boundaries that limit charge separation. Conventional methods of heating to enlarge the grain size of the perovskite crystals are limited due to the degradation reaction that converts the perovskite back to its precursor materials at 110 degrees Celsius. A newer technology called intense pulsed light is being used to generate light produced by a xenon plasma lamp at short millisecond pulses to create temperatures exceeding 500 degrees Celsius. The short bursts of heat enable higher temperatures to be reached by the perovskite crystals without degrading the material back to its precursors. Grain sizes have increased by over five times the grain sizes reported using conventional heating procedures.