Probing itinerant carrier dynamics at the diamond surface using single nitrogen vacancy centers

TL;DR

This study uses near-surface nitrogen vacancy centers in diamond to probe the dynamics of itinerant carriers, revealing long carrier lifetimes and providing a new method for surface characterization and charge transport investigation.

Contribution

It introduces a novel approach to study itinerant carrier dynamics at the diamond surface using NV centers, highlighting their potential for surface and device analysis.

Findings

NV centers can be converted to neutral charge state via hole capture.

The hole capture rate is suppressed near the surface.

Carrier lifetime remains long even at the diamond surface.

Abstract

Color centers in diamond are widely explored for applications in quantum sensing, computing, and networking. Their optical, spin, and charge properties have been extensively studied, while their interactions with itinerant carriers are relatively unexplored. Here we show that NV centers situated within 10 nm of the diamond surface can be converted to the neutral charge state via hole capture. By measuring the hole capture rate, we extract the capture cross section, which is suppressed by proximity to the diamond surface. The distance dependence is consistent with a carrier diffusion model, indicating that the itinerant carrier lifetime can be long, even at the diamond surface. Measuring dynamics of near-surface NV centers offers a new tool for characterizing the diamond surface and investigating charge transport in diamond devices.