Observation of interface carrier states in no-common-atom heterostructures ZnSe/BeTe

TL;DR

This paper provides experimental evidence and theoretical confirmation of intrinsic interface carrier states in ZnSe/BeTe heterostructures with no common atom at the interface, highlighting their high density and potential impact on electronic properties.

Contribution

It demonstrates the existence of interface carrier states in no-common-atom heterostructures through experimental and theoretical methods, which was previously unconfirmed.

Findings

Interface states are located inside the effective band gap.

States are characterized by high density and capture rate.

Existence depends on the type of interface (ZnTe-type vs BeSe-type).

Abstract

Existence of intrinsic carrier interface states in heterostructures with no common atom at the interface (such as ZnSe/BeTe) is evidenced experimentally by ellipsometry and photoluminescence spectroscopy. These states are located on interfaces and lie inside the effective band gap of the structure; they are characterized by a high density and high carrier capture rate. A tight binding model confirms theoretically the existence of these states in ZnSe/BeTe heterostructures for a ZnTe-type interface, in contrast to the case of the BeSe-type interface for which they do not exist.