Ga2O3based multilevel solar-blind photomemory array with logic, arithmetic, and image storage functionsElectronic supplementary information (ESI) available: HRTEM images of Ga2O3; high-resolution O 1s XPS spectra of Ga2O3; readout current curves of the photomemories with and without β-Ga2O3; dependence of the spike current and relaxation current of the photomemory cell on the intensity of the 254 nm illumination; multilevel storage obtained by changing the exposure time; retention performance of the storage state; performance uniformity of the photomemory cells; multilevel image storage under different solar-blind light exposure times. See DOI: 10.1039/d1mh01304a

Photomemories offer great opportunities for multifunctional integration of optical sensing, data storage, and processing into one single device. However, little attention has been paid to photomemories working in the solar-blind region so far, which may have unique advantages of insusceptibility to ambient light and higher capacity. Herein, we propose and demonstrate a Ga2O3based solar-blind photomemory array with logic, arithmetic, and optoelectronic memory functions. The device shows n-type field effect-transistor performance with an on/off ratio as high as 106, a responsivity of 8 × 103A W−1, and a detectivity of 1.42 × 1014Jones, all of which are amongst the best values ever reported for Ga2O3based photodetectors. Based on the trapping and de-trapping process of holes in Ga2O3, multilevel data storage can be realized from the device. Simultaneously, the optical and electrical mixed basic logic of reconfigurable “AND” and “OR” operations have been realized in a single cell through the co-regulation of solar-blind light and the grid voltage. In addition, the photomemory can perform counting and addition operations, and the photomemory array can be utilized to realize solar-blind image storage. The results suggest that Ga2O3may have potential applications in high-performance information storage, computing, and communications.