Improved Performances of CVD‐Grown MoS2 Based Phototransistors Enabled by Encapsulation

Abstract

AbstractMoS2 as a semiconducting 2D material has been a promising candidate for the next generation of optoelectronics due to its atomic thickness, mechanical flexibility, complementary metal‐oxide‐semiconductor compatibility, and large‐scale manufacturing. However, the poor quality such as low mobility and numerous defects has much affected the corresponding device performances, which has limited their wide applications. Here, an effective strategy is proposed to significantly improve the quality of the chemical vapor deposition (CVD)‐grown monolayer MoS2 by the encapsulation technique with atomic layer deposition Al2O3. Benefiting from the passivation of defects and suppression of charge Coulomb scattering, the mobility can be improved by more than one order of magnitude, reaching up to 62.5 cm2 Vs−1. As a result, the photodetection performances in terms of response time, responsivity, and detectivity are also improved up to 20 ms, 1.1 × 104 A W−1, and 3.1 × 1012 Jones, respectively. The developed encapsulation technique here for the improvement of film quality and device performance can further enable the practical application of large‐scale 2D materials‐based electronics and photodetectors.