AN IMAGING DEVICE COMPRISING AN AMX3
ORGANOMETALLIC PEROVSKITE MATERIAL
BACKGROUND
The present invention relates generally to imaging
devices and more particularly to an
imaging device with improved quantum efficiency.
Generally, photodiodes
are made of either inorganic semiconductors, such as, silicon, Germanium,
Indium gallium arsenide, and Lead sulfide, Cadmium telluride (CdTe), among
others, or organic semiconductors, such as, one that is based on a blend of
regioregular poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl
ester (PCBM), among others.
A conventional
photodiode employs a perovskite oxide, such as, Strontium titanate (SrTiO3).
The photodiode includes Titanium dioxide (TiO₂) nanocrystalline film that is prepared
on SrTiO₃ substrate to form an n-n heterojunction active layer.
Interdigitated gold (Au) electrodes are deposited on top of TiO₂
film to fabricate a modified heterojunction metal-semiconductor-metal (HMSM)
ultraviolet photodetector. The TiO₂/SrTiO₃
heterojunction finds excellent application in fabricating high performance UV
photodetectors.
Other
conventional solar cells are made of organometallic perovskite, in particular, methylammonium
lead halide (CH3NH3PbX3), where X represents a
halogen, such as, chlorine (Cl), bromine (Br), or iodine (I), or methylammonium
tin iodide (CH3NH3SnI3). While solar cells are
generally optimized to maximize charge extraction under irradiation,
photodiodes are required to minimize dark current, which likely require one or
two blocking layers and are usually operated under bias.
However, quantum
efficiency of the conventional photodiodes and solar cells is reduced due to
optical losses, such as, transmission and reflection.
Therefore,
it would be desirable to have an imaging device
that includes a photodiode with improved quantum efficiency.
DETAILED DESCRIPTION
An imaging
device that includes a perovskite material is disclosed. The imaging device includes a substrate, a thin
film transistor (TFT) array and a photodiode. The photodiode includes an AMX3-type
(perovskite) material, wherein A inclu...