National Facility for High Resolution CL Analysis of Photovoltaic and Optoelectronic Devices

A new national facility will let researchers fire electron beams at solar cells and LEDs to spot individual atomic-scale defects that limit their performance. Today’s solar panels and light-emitting diodes waste energy because tiny imperfections in their crystal structure trap charge or create heat. These defects are smaller than the wavelength of visible light, so standard optical microscopes cannot see them. The facility combines two instruments: a scanning electron microscope with a plasma-focused ion beam to cut out defective regions for transmission electron microscopy, and a dedicated scanning transmission electron microscope that maps luminescence at the nanoscale. No other facility in the world offers this combined capability. If the facility works as intended, UK researchers and companies will be able to diagnose exactly why a new photovoltaic material underperforms and then fix it. That could accelerate the development of more efficient solar cells, brighter LEDs, and better photodetectors—technologies that underpin renewable energy grids, displays, and optical communications. The research is applied: it directly targets device engineering rather than fundamental discovery, though the nanoscale insights may also reveal new physics in how light and matter interact at the smallest scales.