Kim, Jeehoon Song, Seungho Lee, Jong-Min Nam, San Kim, Jaehyun Hwang, Do Kyung Park, Sung Kyu Kim, Yong-Hoon 2024-01-19T09:03:26Z 2024-01-19T09:03:26Z 2023-05-18 2023-08 1613-6810 https://pubs.kist.re.kr/handle/201004/113470 Broad spectral response and high photoelectric conversion efficiency are key milestones for realizing multifunctional, low-power optoelectronic devices such as artificial synapse and reconfigurable memory devices. Nevertheless, the wide bandgap and narrow spectral response of metal-oxide semiconductors are problematic for efficient metal-oxide optoelectronic devices such as photonic synapse and optical memory devices. Here, a simple titania (TiO2)/indium-gallium-zinc-oxide (IGZO) heterojunction structure is proposed for efficient multifunctional optoelectronic devices, enabling widen spectral response range and high photoresponsivity. By overlaying a TiO2 film on IGZO, the light absorption range extends to red light, along with enhanced photoresponsivity in the full visible light region. By implementing the TiO2/IGZO heterojunction structure, various synaptic behaviors are successfully emulated such as short-term memory/long-term memory and paired pulse facilitation. Also, the TiO2/IGZO synaptic transistor exhibits a recognition rate up to 90.3% in recognizing handwritten digit images. Moreover, by regulating the photocarrier dynamics and retention behavior using gate-bias modulation, a reconfigurable multilevel (>= 8 states) memory is demonstrated using visible light. English Wiley - V C H Verlag GmbbH & Co. Metal-Oxide Heterojunction Optoelectronic Synapse and Multilevel Memory Devices Enabled by Broad Spectral Photocarrier Modulation Article 10.1002/smll.202301186 1 Small, v.19, no.35 Small 19 35 N scie scopus 000978065700001 2-s2.0-85154046227 Chemistry, Multidisciplinary Chemistry, Physical Nanoscience & Nanotechnology Materials Science, Multidisciplinary Physics, Applied Physics, Condensed Matter Chemistry Science & Technology - Other Topics Materials Science Physics Article TIO2 PHOTOTRANSISTORS RESPONSIVITY pattern recognition TiO2 IGZO heterostructures transistors multilevel memory optoelectronic synapses