A blue-violet enhanced BDJ photodetector and its applications in the probe chip measurements of the LEDs for solid-state lighting

A blue-violet enhanced buried double p–n junction (BDJ) photodetector with its characteristics is reported in this manuscript. It was fabricated on high resistivity float-zone silicon substrate by using ion implantation and exhibits low leakage currents. It can measure both the light intensity as a photometric detector and the wavelength of quasi-monochrome light as a wavelength sensor simultaneously. It was optimized to operate at wavelength from 380 nm to 780 nm in which the light emitting diodes (LEDs) for solid-state lighting is most interested. The resolution for the wavelength measurement of the photodetector is better than 1 nm. The probe chip tests of violet, blue, green and red LED chips have been demonstrated using the fabricated detector. This simple, fast and reliable method provides an alternative to low cost and fast examination technique for LED chips in vast production.