Real-time and on-chip surface temperature sensing of GaN LED chips using PbSe quantum dots.

PbSe quantum dots (QDs) were employed as real-time and on-chip temperature sensors to monitor the surface temperature of GaN LED chips. The temperature-dependent photoluminescence spectra were achieved and confirmed to be a good method for surface temperature sensing in a micro- to nano-region. The nanosized QD sensors did not influence the LED emission spectrum due to their infrared emission and little absorption. The surface temperature of GaN LED chips was analyzed at different working times and voltages. The temperature sensitivity characterized by the photoluminescence peak position of PbSe QDs was found to be 0.15 nm °C(-1) in a range of 30-120 °C and the precision was determined to be ± 3 °C. The QD surface temperature sensors were confirmed to have good reversibility and repeatability.