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Updated: Mar 8, 2026

Monovalent Cation Doping of CH3NH3PbI3 for Efficient Perovskite Solar Cells
Published on: March 19, 2017
Photodiode Response in a CH3NH3PbI3/CH3NH3SnI3 Heterojunction
Massimo Spina1, László Mihály2, Károly Holczer3
1Laboratory of Physics of Complex Matter, Ecole Polytechnique Fédérale de Lausanne , CH-1015 Lausanne, Switzerland.
Abstract:
Here we report another surprising feature of the methylammonium metal halide material family, the phototunability of the diode response of a heterojunction made of CH3NH3PbI3 and its close relative, CH3NH3SnI3. In the dark state the device behaves as a diode, with the Sn homologue acting as the "p" side. The junction is extremely sensitive to illumination. A complete reversal of the diode polarity, the first observation of its kind, is seen when the junction is exposed to red laser light of 25 mW/cm2 or larger power density. This finding opens up the possibility for a novel class of optoelectronic devices.
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