Isotope Synergetic Effect on Hybrid Organic–Inorganic Perovskite Single Crystal Carrier Transport and High-Performance Photodetectors

Isotope engineering finely manipulates atomic composition, significantly affecting key characteristics such as charge transport and molecular vibrations in optoelectronic materials. A new perspective is presented for optimizing the electronic properties and performance of perovskite photodetectors. In this work, methylammonium lead iodide single crystals (SCs) with different deuterium substitution levels (DxMAPbI3, x = 0, 0.15, 0.99) have been successfully grown. Moderate deuteration balances hyperfine interactions of organic molecules and phonons in organometallic materials and electron–phonon coupling. In contrast to the degradation in D0.99MAPbI3, the carrier lifetime and carrier mobility in D0.15MAPbI3 have been significantly enhanced to 328.2 ns and 296.2 cm2 V–1 s–1, respectively, which are two and four times that of MAPbI3. The detectivity (D*), external quantum efficiency (EQE), and responsivity (R) of the D0.15MAPbI3 photodetector increased to 518%, 708%, and 1067%, respectively. D0.15MAPbI3 has higher decomposition temperatures and reduced photocurrent degradation. Our research provides an effective strategy to develop high-performance optoelectronic devices.