Solution-processable integrated CMOS circuits based on colloidal CuInSe2 quantum dots

Abstract

The emerging technology of colloidal quantum dot electronics provides an opportunity for combining the advantages of well-understood inorganic semiconductors with the chemical processability of molecular systems. So far, most research on quantum dot electronic devices has focused on materials based on Pb- and Cd chalcogenides. In addition to environmental concerns associated with the presence of toxic metals, these quantum dots are not well suited for applications in CMOS circuits due to difficulties in integrating complementary n- and p-channel transistors in a common quantum dot active layer. Here, we demonstrate that by using heavy-metal-free CuInSe2 quantum dots, we can address the problem of toxicity and simultaneously achieve straightforward integration of complimentary devices to prepare functional CMOS circuits. Specifically, utilizing the same spin-coated layer of CuInSe2 quantum dots, we realize both p- and n-channel transistors and demonstrate well-behaved integrated logic circuits with low switching voltages compatible with standard CMOS electronics.

Heavy‐Metal‐Free Quantum Dot‐Based Flexible Electronics

“…Instead, InP QDs are used for their luminescence in commercial QD TVs. More recent research efforts have been spent on developing heavy‐metal‐free QD systems, including III‐V 16,17 and I‐III‐VI 2 18,19 QDs for electronics. The progress made by both academic institutions and industry further advances the commercialization of QD flexible electronics.…”

“…Exploiting the tunable doping characteristics of CISe QDs, Klimov and colleagues recently integrated complementary metal‐oxide‐semiconductor (CMOS) circuits 84 . Colloidally synthesized CISe QDs are deposited to form thin films followed by halide‐based ligand exchange ( Fig.…”

“…Inset: photograph of an array of inverters (scale bar: 5 mm). (d) Schematics (top), photograph (bottom left), and output voltage corresponding to the input signals (bottom right) of the CISe QD CMOS NAND gate 84 …”

Intrinsic and Extrinsic Exciton Recombination Pathways in AgInS 2 Colloidal Nanocrystals

“…Owing to their typically broad and featureless luminescence spectrum, CuInS 2 NCs have also been proposed as active materials in single-component white LEDs [23,24], enabling one to bypass the limitation of different turn-on voltages and degradation dynamics typically encountered in white-LEDs based on mixtures of NCs with complementary electroluminescence spectra [25,26]. Because of their relevance for applications, numerous studies have been devoted to investigating the fundamental physical processes responsible for the distinctive optical and electronic behaviors of CuInS 2 NCs [7,20,[27][28][29][30], as well as to identify and suppress competitive nonradiative processes affecting the luminescence yield [31]. Based on the strong similarities between the optical and magneto-optical behaviors of off-stoichiometry CuInS 2 NCs and Cu-doped II-VI chalcogenides [32][33][34], in such NCs, the large Stokes shift and long emission lifetime are typically ascribed to the recombination of a photogenerated conduction band (CB) electron with a photohole localized on an intragap defect state associated with Cu + defects [28,35].…”

Present and Perspectives of Photoactive Porous Composites Based on Semiconductor Nanocrystals and Metal-Organic Frameworks

“…Generally, they possess diameters smaller than the exciton Bohr radius (below 10 nm), which endows them with remarkable optical and electronic properties due to quantum confinement effects, and present discrete electronic energy levels that can be precisely controlled by the nanocrystal size and shape [ 15 , 16 ]. Therefore, the fact that they have easily tuneable and size-dependent photophysical properties makes quantum dots of great interest in various fields of application such as flexible transistors [ 17 ], solar cells [ 18 ], light-emitting diodes (LEDs) [ 19 ], lasers [ 20 ], quantum computing [ 21 ], photodetectors [ 22 ], catalysis [ 23 ], cell biology research, imaging, and diagnostics [ 24 ].…”