Resistive-switching tunability with size-dependent all-inorganic zero-dimensional tetrahedrite quantum dots

Abstract

All-inorganic zero-dimensional (0D) tetrahedrite (Cu 12 Sb 4 S 13 , CAS) quantum dots (QDs) have attracted extensive attention due to their excellent optical properties, bandgap tunability, and carrier mobility. In this paper, various sized CAS QDs (5.1, 6.7, and 7.9 nm) are applied as a switching layer with the structure F:SnO 2 (FTO)/CAS QDs/Au, and in doing so, the nonvolatile resistive-switching behavior of electronics based on CAS QDs is reported. The SET/RESET voltage tunability with size dependency is observed for memory devices based on CAS QDs for the first time. Results suggest that differently sized CAS QDs result in different band structures and the regulation of the SET/RESET voltage occurs simply and effectively due to the uniform size of the CAS QDs. Moreover, the presented memory devices have reliable bipolar resistive-switching properties, a resistance (ON/OFF) ratio larger than 10 4 , high reproducibility, and good data retention ability. After 1.4 × 10 6 s of stability testing and 10 4 cycles of quick read tests, the change rate of the ON/OFF ratio is smaller than 0.1%. Furthermore, resistiveswitching stability can be improved by ensuring a uniform particle size for the CAS QDs. The theoretical calculations suggest that the space-charge-limited currents (SCLCs), which are functioned by Cu 3d, Cu 3p and S 3p to act as electron selftrapping centers due to their quantum confinement and form conduction pathways under an electric field, are responsible for the resistive-switching effect. This paper demonstrates that CAS QDs are promising as a novel resistive-switching material in memory devices and can be used to facilitate the application of next-generation nonvolatile memory.

Size-controlled resistive switching performance and regulation mechanism of SnO₂ QDs

“…材料制备过程中的缺陷、掺杂与空位等因素都 会影响其阻变行为. 研究者提出了许多阻变效应的 作用机理, 如导电细丝形成/断裂 [12,27,28] 、陷阱填充 限制电流 [13,29,30] 与界面肖特基势垒调制 [18,31,32] 等, 得到了广泛认可; 而量子点材料的阻变机理较为复 电细丝/形成断裂机理的基本特征 [33,34] ; 同时I-V 曲线中并未出现界面肖特基势垒调制机理常有的 正 负 向 偏 压 LRS电 流 不 对 称 现 象 [35,36] , 这 表 明 SnO 2 QDs的阻变效应并非由单一的阻变机理控制.…”

Efficient Photocatalytic CO2 Reduction by the Construction of Ti3C2/CsPbBr3 QD Composites

“…CsPbBr 3 quantum dots (QDs), as the typical halide perovskite materials, are promising candidates for the photoreduction of CO 2 with the proper energy band structure (2.4 eV), excellent light responses, and long electron–hole diffusion lengths. − Sun et al synthesized CsPbBr 3 QDs (3–12 nm) as a new type of photocatalytic material, and these CsPbBr 3 QDs with a size of 8.5 nm achieved efficient yields of 4.3, 1.5, and 0.1 μmol g –1 h –1 as the formation rates of CO, CH 4 , and H 2 , respectively. However, CsPbBr 3 QDs show a low generation rate in the photoreduction of CO 2 to CO due to their rapid recombination of photoinduced holes and electrons.…”