Large Band-Edge Photocurrent Peak in Thick Methylammonium Lead Iodide Photosensors with Symmetric Metal Electrodes

作者：Hantz Peter^*; Sarlos Ferenc; Jalsovszky Istvan; Plesz Balazs

来源：ACS Photonics, 2017, 4(9): 2171-2178.

DOI：10.1021/acsphotonics.7b00270

• photocurrent spectroscopy
• near-band-gap peak
• lead halide perovskite
• optical absorption
• radiation direction
• reaction-diffusion model

This study examines the photocurrent (photoconductivity) spectra of thick methylammonium lead iodide perovskite layers coupled to symmetric metal electrodes. A large photocurrent peak has been observed in the near-band-gap wavelength region. The origin of this current peak is related to an interplay between the penetration depths of light having a certain wavelength and its ability to raise the concentration of the charge carriers. A model including the generation, position-specific or uniform recombination, as well as diffusion of charge carrier pairs, made it possible to reproduce the experimental findings. Besides the microscopic approach, we also present a phenomenological model and a simulation providing the conductance for an arbitrary relative orientation of the illuminating beam and the field imposed by the electrodes. The results enabled us to outline the functioning principle of a sensor for determining the angle of incidence of electromagnetic radiation. Furthermore, a method for estimating optical absorption spectra from photocurrent spectra is delineated.

• 出版日期2017-9