Nanometer-scale compositional variations in III-V semiconductor heterostructures characterized by scanning tunneling microscopy

Abstract

Nanometer-scale compositional structure in InAs x P 1Ϫx /InN y As x P 1ϪxϪy //InP heterostructures grown by gas-source molecular beam epitaxy and in InAs 1Ϫx P x /InAs 1Ϫy Sb y /InAs heterostructures grown by metalorganic chemical vapor deposition has been characterized using cross-sectional scanning tunneling microscopy. InAs x P 1Ϫx alloy layers are found to contain As-rich and P-rich clusters with boundaries formed preferentially within ͑111͒ and ͑111͒ crystal planes. Similar compositional clustering is observed within InN y As x P 1ϪxϪy alloy layers. Imaging of InAs 1Ϫx P x /InAs 1Ϫy Sb y superlattices reveals nanometer-scale clustering within both the InAs 1Ϫx P x and InAs 1Ϫy Sb y alloy layers, with preferential alignment of compositional features in the ͓112͔ direction. Instances are observed of compositional features correlated across a heterojunction interface, with regions whose composition corresponds to a smaller unstrained lattice constant relative to the surrounding alloy material appearing to propagate across the interface.

Understanding semiconductor nanostructures via advanced electron microscopy and spectroscopy

“…Previously, the use of scanning tunneling microscopy (STM) to identify atomic ordering has been reported [117]. Conventional HRTEM imaging associated with diffraction pattern methods also can provide information about the atomic ordering [111,115,[118][119][120].…”

High-Performance Photodetectors Using a 2D MoS2/3D-AlN Structure

“…The properties of a heterostructure composed of AlN and MoS 2 are affected by many factors. For example, lattice mismatch will cause a certain degree of piezoelectric polarization in AlN, and the properties at the interface including charge accumulation and potential energy steps will also be affected accordingly. , Due to the existence of a polarization effect, the accumulation of polarization charges at the interface will have an adjustment effect on the photoelectric properties of MoS 2 . However, there are few studies on the AlN/MoS 2 heterostructure in this field.…”