THE Chinese Academy of Science reports that researchers in China have used strain engineering to improve the light output power of 530nm green light-emitting diodes (LEDs) by 28.9% at 150mA current injection [Hongjian Li et al, Appl. Phys. Express, vol6, p052102, 2013]. The research was carried out by Chinese Academy of Sciences’ Institute of Semiconductors, Beijing, and University of Hong Kong. Schematic of epitaxial material for conventional and shallow quantum well (SQW) LEDs (Figure 1). Light output power–current–voltage (L&ndas...