Solution-Processable Carbon and Graphene Quantum Dots Photodetectors

Carbon and graphene quantum dots (C/GQDs) have attracted significant interest for their strengths for optoelectronic, energy, and biological applications since their recent addition to the carbon family. With abundant presence, chemical stability, nontoxic nature, emerging quantum dots promise enormous potential towards solution-processable, low-cost optoelectronic applications. This chapter mainly focuses on the applications of C/GQDs in high-performance photodetectors. It begins with encompassing the synthesis routes and methods to control the size and properties of the quantum dots. Then, device structures, configurations, and fabrication techniques are described along with potential applications in photodetectors. Special attention is made to explain the working mechanisms of the quantum dots-based photodetectors. Important device parameters of photodetectors such as Responsivity (R), external quantum efficiency (EQE), specific detectivity (D*∗) and photoconductive gain (G) are briefly explained, with references to the factors affecting them. Furthermore, the chapter describes the use of C/GQDs in hybrid structures with inorganic and layered two-dimensional (2D) materials and interface engineering involved in device design to improve the performance of photodetectors. Finally, we summarize the current challenges and issues of the C/GQDs-based photodetectors and strategies towards future applications and device performance improvements.