PV & Self-Healing Semiconductors

Overview

A central challenge in thin-film photovoltaics is that defects — formed during deposition or introduced by illumination, heat, and moisture — degrade device performance over time. We study a class of low-dimensional (quasi-1D and quasi-2D) semiconductor materials that exhibit unusual tolerance to defects and, in some cases, the ability to spontaneously heal structural and electronic damage. Understanding and harnessing this self-healing behavior is the core question driving this research thread.

Research Directions

Quasi-1D semiconductors for SWIR solar cells. Materials with one-dimensional crystal structures exhibit anisotropic transport and unique defect physics. We grow and characterize quasi-1D chalcogenide and halide semiconductors whose bandgaps are well-matched to the short-wave infrared (SWIR) portion of the solar spectrum — a spectral window largely untapped by current photovoltaic technologies.

Defect chemistry and self-healing mechanisms. We investigate the atomic origins of self-healing: which defect types are mobile, what drives their annihilation, and how processing conditions (temperature, atmosphere, illumination) modulate defect populations. Techniques include temperature-dependent electrical measurements, photoluminescence, and first-principles-guided defect modeling.

Thin-film device integration. We translate materials insights into working solar cell devices, studying how interfaces between absorber, transport layers, and contacts determine open-circuit voltage losses and long-term stability.

Why It Matters

Extending photovoltaic absorption into the SWIR enables tandem and multi-junction cell architectures with efficiencies beyond the single-junction Shockley–Queisser limit. Self-healing absorbers could simultaneously reduce degradation rates, addressing the two largest remaining barriers to terawatt-scale solar deployment.