High-Efficiency X-ray Sensing with Recyclable Perovskite–Graphene Heterostructured Transistors

Abstract

We present a recyclable perovskite−graphene heterostructure that demonstrates ultrahigh X-ray detection sensitivities over 10 8 μC/Gy air •cm 2 for medical imaging applications. The high mobility of the graphene pixel is preserved to over 1200 cm 2 /V•s after perovskite deposition and enables large conversion efficiency for ultrahigh sensitivity. Increasing the operational bias of the graphene channel increased the X-ray detection signal-to-noise ratio from 30 to over 200. The perovskite can be washed off by an organic solvent at room temperature without damaging the graphene. Redepositing the perovskite layer retains the detectors' high gain, making our heterostructure X-ray detector a recyclable device. The perovskite−graphene device exhibits robust operation given 10,000 gate sweeps and multicycle X-ray irradiations. Here we have demonstrated a high-performance, low-cost, plug-and-play solution with a recyclable design that could significantly reduce the manufacturing and maintenance costs associated with X-ray cameras in medical imaging.

Dielectric Screening and Charge-Transfer in 2D Lead-Halide Perovskites for Reduced Exciton Binding Energies

“…Two dimensional (2D) organic–inorganic Ruddlesden–Popper lead halide perovskites (A’) 2 (A) n −1 Pb n X 3 n +1 where [A = Cs + , CH 3 NH 3 + , HC­(NH 2 ) 2 ; A’ represents variable spacer cations; X = Cl,Br,I; n is layer thickness], have shown considerable success for optoelectronic applications including photovoltaics, − light-emitting diodes, and photodetectors in the UV–vis and X-ray − regime. These classes of materials can be tuned physically or chemically.…”