Kenji Ueda1
Waseda University1
Diamond/graphene (carbon sp<sup>3</sup>-sp<sup>2</sup>) interfaces have attracted much attention because they are sources of various interesting electronic phenomena. Many theorists suggest hybrid structures of diamond and graphene exhibit interesting electronic characters, however there are only limited experimental reports on electronic characters of carbon sp<sup>3</sup>-sp<sup>2</sup> interfaces.<br/>Recently, we newly found that diamond/graphene heterojunctions became photo-controllable memristors (photomemristors), which are optically controllable memory-resistors with both photo-switching and memory functions [1, 2]. The junctions also showed characteristic response to optical pulses, and brain mimic memory functions, that is, change of photomemory time from shorter to longer memory time depending on irradiated numbers of optical pulses [3]. These behaviors are analogous to transitions from short to long-term memory states of biological synapses. In addition, arrays using the diamond/graphene junctions can function as special types of image sensors which have selective memory function of optical information depending on the relative importance of the data as human brains perform.<br/>These results suggest the diamond/graphene (C sp<sup>3</sup>-sp<sup>2</sup>) junctions are promising for fabricating novel neuromorphic visual information processing systems that are modulated by specific interests.<br/><br/>Ref.:<br/>[1] K. Ueda et al., J. Mater. Res., 34 (2019) 626.<br/>[2] K. Ueda et al., Appl. Phys. Lett. 117 (2020) 092103.<br/>[3] Y. Mizuno, Y. Ito, and K. Ueda, Carbon. 182 (2021) 669.