Laser-Based Defect Reduction in Wide Bandgap Semiconductors Used in Radiation-Voltaics Devices: Radiation Hardening and Annealing

Selim Elhadj | 19-FS-021


Radiation voltaics can provide a source of long-lasting electrical power (over 100 years, for example) in remote locations or within implantable medical devices. However, permanent defects can be generated by radiation flux compromising the semiconductor material. Therefore, more robust semiconductors could increase performance and reliability in radiation-based electronic devices.

We studied whether laser illumination at sub-bandgap wavelengths of semiconductors, especially those used for radiation voltaics, could anneal defects generated during radiation exposure (beta and alpha radiation). Defect annealing was probed on a set of silicon carbide (SiC) samples using in situ monitoring of the photoluminescence emissions from UV- to near-infrared spectra under UV excitation (broadband or laser at λ L = 351 nm). No significant effect was found using 1064 nm wavelength light as the annealing source up to the laser damage threshold fluence of the nanosecond pulsed laser (10 Hz rep-rate). Based on the results of this limited study, laser annealing was not effective in reducing radiation damage in SiC.

Impact on Mission

Our research leveraged Lawrence Livermore National Laboratory's core competency in advanced materials and expanded the Laboratory's expertise in materials for energy storage.