Quantum dot photoelectric detector based on atomic layer deposition and preparation method thereof

Abstract

The invention belongs to the preparation field of the optical material, and discloses a quantum dot photoelectric detector based on atomic layer deposition, and a preparation method thereof. The preparation method comprises the following steps: spinning-coating a quantum dot solution on a clean substrate to prepare a first quantum dot thin film, and then dropping an organic matter ligand solutionon the first quantum doe thin film to cover the same, and standing for a certain time, cleaning by using a solvent after the ligand exchange is accomplished, thereby accomplishing the preparation of the ligand exchange layer thin film; spinning-coating the quantum dot solution on the ligand exchange layer thin film to prepare a monolayer quantum dot thin film; performing atomic layer deposition oninert atmosphere so as to sufficiently passivate the monolayer quantum dot thin film, repeating the above steps so as to acquire a passivation layer thin film; and evaporating electrode on the passivation layer thin film to manufacture the quantum dot photoelectric detector. The quantum dot thin film surface is passivated by adopting the atomic layer deposition technology, the light and dark current ratio of the device can be improved, the device performance of the detector is optimized, and a PN-junction dual-layer structure is formed, and the response speed can be effectively improved.

Description

technical field [0001] The invention belongs to the field of optical material preparation, and more specifically relates to a quantum dot photodetector based on atomic layer deposition and a preparation method thereof. Background technique [0002] Quantum dots, also known as nanocrystals, are nanoparticles composed of II-VI or III-V elements. The particle size of quantum dots is generally between 1nm and 10nm. Since electrons and holes are quantum-confined, the continuous energy band structure becomes a discrete energy level structure with molecular characteristics, which can emit fluorescence after being excited. The emission spectrum of quantum dots can be controlled by changing the size of the quantum dots. It has good photostability, wide excitation spectrum and narrow emission spectrum. It has a wide range of applications in the fields of solar cells, light-emitting devices, and optical biomarkers. application prospects. [0003] At present, in the field of quantum d...

AI Technical Summary

Problems solved by technology

However, the photodetector prepared by this method has a large dark current and a small photocurrent. After the ligand exchange, the quantum dot photodetector has the disadvantages of low photo-dark current ratio and slow response time, and the device performance is very poor.

[0004] In order to solve the shortcomings of poor performance of single-layer films, metal nanocrystals such as Ag or Au are doped into the quantum dot film, which prolongs the lifetime of photon carriers and improves the photocurrent of the device, but the introduced traps will slow down the response of the device. speed, the dark current of the device will also increase accordingly, and the introduction of noble metal nanocrystals will also greatly increase the manufacturing cost, which is not suitable for the mass production of quantum dot photodetectors

Images