# Three-dimensional charge transport mapping by two-photon absorption edge transient-current technique in synthetic single-crystalline diamond

## TL;DR

This paper introduces a novel 3D charge transport mapping technique using two-photon absorption transient current measurements in synthetic single-crystalline diamond, enabling high-resolution spatial analysis of charge transport properties.

## Contribution

It presents a new method combining two-photon absorption with transient current measurements to achieve 3D mapping of charge transport in wide bandgap semiconductors.

## Key findings

- 3D charge transport maps of diamond obtained
- Spatial variations in charge transport characterized
- Method validated against X-ray diffraction topography

## Abstract

We demonstrate the application of two-photon absorption transient current technique to wide bandgap semiconductors. We utilize it to probe charge transport properties of single-crystal Chemical Vapor Deposition (scCVD) diamond. The charge carriers, inside the scCVD diamond sample, are excited by a femtosecond laser through simultaneous absorption of two photons. Due to the nature of two-photon absorption, the generation of charge carriers is confined in space (3-D) around the focal point of the laser. Such localized charge injection allows to probe the charge transport properties of the semiconductor bulk with a fine-grained 3-D resolution. Exploiting spatial confinement of the generated charge, the electrical field of the diamond bulk was mapped at different depths and compared to an X-ray diffraction topograph of the sample. Measurements utilizing this method provide a unique way of exploring spatial variations of charge transport properties in transparent wide-bandgap semiconductors.