Rapid thickness reading of CH sub(3)NH sub(3)PbI sub(3 ) nanowire thin films from color maps

• Published in: Physica status solidi. A, Applications and materials science Vol. 213; no. 8; pp. 2017 - 2023
• Main Authors: Spina, Massimo, Grimaldi, Claudio, Nafradi, Balint, ro, Laszlo, Horvath, Endre
• Format: Journal Article
• Language: English
• Published: 01.08.2016
• Subjects: Calibration; Color; Nanowires; Optoelectronic devices; Perovskites; Photovoltaic cells; Solar cells; Thin films
• ISSN: 1862-6300; 1862-6319
• DOI: 10.1002/pssa.201533067

Hybrid halide perovskite photovoltaic materials show a remarkable light conversion efficiency in various optoelectronic devices. In the fabrication of these solar cells, light emitting diodes, laser and photodetector prototypes the thickness of the perovskite is an important parameter since the light is absorbed within a thin layer of a few hundred nanometers. Nevertheless, making perovskite coatings with various solution-based and evaporation methods showing highly reproducible thickness and area coverage is still an issue. Therefore, rapid and reliable quality-control of the film morphology is needed. This report shows a simple, rapid, and calibration-free method for reading the thickness directly from the color map of nanowire perovskite films seen in standard optical microscope with visible light. The authors report on a facile, rapid, and calibration-free method to extract automatically the thickness of CH sub(3)NH sub(3)PbI sub(3 ) nanowire thin-films on dielectric surfaces directly from optical images. Their method amounts to minimize a suitable defined distance in the red-green-blue color space which measures the difference between the observed and calculated colors of perovskite nanowires.