Integrated advantages from perovskite photovoltaic cell and 2D MoTe2 transistor towards self-power energy harvesting and photosensing

Perovskite photovoltaic (PV) cell researches have been extensively conducted due to its unprecedentedly excellent power conversion efficiencies (PCEs), which are reported to be over 23.7% in maximum. Despite the high PCEs, there are several unresolved issues on optimal interface states in the cell and device stabilities. Moreover, beyond the simple PV device issues, extended device or circuit applications have rarely been reported although it seems equally important to fully reveal the self-power energy harvesting functions of the perovskite cells to modern ubiquitous environment. Here, we integrate a realistic self-power circuit utilizing a few nm-thin molybdenum ditelluride (MoTe2) field effect transistors (FETs) as well as perovskite PV cells. The PV cells intrinsically show more than 0.9 V of open circuit voltage (VOC) under artificial sun (AM 1.5) or visible photon illumination, so we thus used a red-light emitting diode (LED) to simply generate ~1 V of photovoltage. Two modes for practical operation were consequently observed from the circuit, depending on the light intensity: self-power current/voltage source mode (high intensity) and photosensor mode (low intensity). We now conclude that our self-power circuit approaches integrating perovskite cells and 2D MoTe2 FET could attract much attention for future ubiquitous electronics and energy harvest applications.