Size-dependent characteristics of inorganic ligand-exchanged InAs quantum dots for optoelectronic devices

Abstract

Quantum Dot (QD) is small crystals with a diameter smaller than exciton Bohr radius that emit light of various colors when excited by electric or light stimulus. Due to the high color purity of the emitted light, quantum dots are used as fluorescent materials to enhance the characteristics of displays, or to attach reactive molecules that respond to specific cells for cell imaging. Recently, Indium Arsenide (InAs) QDs were receiving attention as promising semiconductor in near- infrared region. In automobile mobile systems, Light Detection and Ranging (LiDAR) technology is necessary for immediate sensing of hazardous circumstances. InAs QDs are promising candidates for applying detecting devices substituting high-toxic particles such as lead chalcogenide QDs. Herein, InAs quantum dots were synthesized by adjusting their size and a ZnSe shell coating was applied to control defects on the surface of the core. Additionally, MCC ligand substitution was carried out to reduce the distance between quantum dots, and this was applied as an electron transport layer in organic solar cells, achieving higher efficiency compared to using only the conventional material, Zn oxide (ZnO). Leveraging the high electron mobility of InAs quantum dots, transistors were fabricated and deposited onto a metal oxide layer to create a photodetector through an all-solution process. Various applications as photodetectors will maximize the advantages of InAs quantum dots, which efficiently absorb light in the infrared region.