<p><b>In this study, for
the first time, self-driven photodetector based on cubic CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub>
large single crystal </b><b>(C-MAPbI<sub>3
</sub>LSC) </b><b>with adjustable
positive-negative signal is fabricated. </b><b>The preparation of MAPbI<sub>3 </sub>large single crystal (MAPbI<sub>3 </sub>LSC)
is realized by the method of growth-drop-growth (GDG). </b><b>The band gap of </b><b>MAPbI<sub>3 </sub></b><b>single crystals </b><b>with Pm-3m (221) space group (6.134×6.134×6.134
Å, 90.00 x 90.00 x 90.00) </b><b>is 1.58 eV.</b> <b>CH<sub>3</sub>NH<sub>3</sub><sup>+</sup> cation
is orientation-disorder </b><b>within the perovskite cubo-octahedral cavity.</b><b> The photocurrent density at 803 nm of the</b><b> C-MAPbI<sub>3 </sub>LSC</b><b> photodetector under different bias voltages
is the highest under different wavelength. The </b><b>responsivities (R),
response time, external quantum efficiencies (EQE) and the detectivity (D) for </b><b>C-MAPbI<sub>3 </sub>LSC</b><b> photodetector at 803 nm wavelength with 1 W
m<sup>-2</sup></b><b>, respectively, is </b><b>508.7 µA/mW, 0.1338 ms, 79.6% and 8.64*10<sup>11</sup> Jones. Notably, </b><b>the C-MAPbI<sub>3 </sub>LSC photodetector
can be self-driven under 0 V bias voltage, in particular, the positive and
negative values of the photocurrent can be adjusted. The proposed mechanism of
poling inducing built-in potential is explained adjustable positive-negative
signal in self-driven photodetector based on cubic CH<sub>3</sub>NH<sub>3</sub>PbI<sub>3</sub>
large single crystal.</b><b></b></p>