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 (D x MAPbI 3, 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 D 0.99 MAPbI 3, the carrier lifetime and carrier mobility in D 0.15 MAPbI 3 have been significantly enhanced to 328.2 ns and 296.2 cm 2 V –1 s –1, respectively, which are two and four times that of MAPbI 3 . The detectivity (D*), external quantum efficiency (EQE), and responsivity (R) of the D 0.15 MAPbI 3 photodetector increased to 518%, 708%, and 1067%, respectively. D 0.15 MAPbI 3 has higher decomposition temperatures and reduced photocurrent degradation. Our research provides an effective strategy to develop high-performance optoelectronic devices.