Photovoltaic and Amplifi ed Spontaneous Emission Studies of High-Quality Formamidinium Lead Bromide Perovskite Films

Journal Article

2016

Published in: Photovoltaic and Amplifi ed Spontaneous Emission Studies of High-Quality Formam…

Arora, Neha . 2016

This study demonstrates the formation of extremely smooth and uniform
formamidinium lead bromide (CH(NH 2 ) 2 PbBr 3 = FAPbBr 3 ) fi lms using
an optimum mixture of dimethyl sulfoxide and N , N -dimethylformamide
solvents. Surface morphology and phase purity of the FAPbBr 3 fi lms are
thoroughly examined by fi eld emission scanning electron microscopy and
powder X-ray diffraction, respectively. To unravel the photophysical properties
of these fi lms, systematic investigation based on time-integrated and timedependent
photoluminescence studies are carried out which, respectively,
bring out relatively lower nonradiative recombination rates and long lasting
photogenerated charge carriers in FAPbBr 3 perovskite fi lms. The devices
based on FTO/TiO 2 /FAPbBr 3 /spiro-OMeTAD/Au show highly reproducible
open-circuit voltage ( V oc ) of 1.42 V, a record for FAPbBr 3 -based perovskite
solar cells. V oc as a function of illumination intensity indicates that the
contacts are very selective and higher V oc values are expected to be achieved
when the quality of the FAPbBr 3 fi lm is further improved. Overall, the devices
based on these fi lms reveal appreciable power conversion effi ciency of
7% under standard illumination conditions with negligible hysteresis. Finally,
the amplifi ed spontaneous emission (ASE) behavior explored in a cavity-free
confi guration for FAPbBr 3 perovskite fi lms shows a sharp ASE threshold at a
fl uence of 190 μJ cm −2 with high quantum effi ciency further confi rming the
high quality of the fi lms.

• Publication Work Type: NPSt Project
• Volume Number: 26
• Issue Number: 17
• Magazine \ Newspaper: Adv. Funct. Mater.
• Pages: 2846 to2854