# Thickness dependence of electron-electron interactions in topological p-n junctions

## TL;DR

This study investigates how electron-electron interactions in topological p-n junctions depend on the thickness of the stacked topological insulators, revealing a decrease in screening with increased thickness and a larger number of 2D states than previously measured.

## Contribution

It provides the first systematic analysis of thickness-dependent electron-electron interactions in topological p-n junctions using transport measurements and theoretical modeling.

## Key findings

- Screening factor decreases with increasing sample thickness.
- Number of 2D states from interactions exceeds that from weak-antilocalization.
- Results align with semi-classical Boltzmann theory.

## Abstract

Electron-electron interactions in topological p-n junctions consisting of vertically stacked topological insulators are investigated. n-type Bi2Te3 and p-type Sb2Te3 of varying relative thicknesses are deposited using molecular beam epitaxy and their electronic properties measured using low-temperature transport. The screening factor is observed to decrease with increasing sample thickness, a finding which is corroborated by semi-classical Boltzmann theory. The number of two-dimensional states determined from electron-electron interactions is larger compared to the number obtained from weak-antilocalization, in line with earlier experiments using single layers.