Bandwidth widening of semiconductors with luminescent layer

LEDs compared to incandescent bulbs have lots of advantages. The only disadvantage of their application are temperature sensitivity and relative narrow spectrum. To widening bandwidth there are several known solutions, e.g. application of phosphor, a group of several different wavelength LEDs, and other structural architectures (tandem LED, etc.). These structures have many disadvantages, e.g. different ageing, loosing of good focusability, etc. One of the possible solutions is application of multiple layers of different composition, and realizes several radiation peaks with luminescence. The intensity of LED emission at different part of the spectrum may vary in opposite direction due to changing the operation temperature. The shift of the emission spectrum of multi wavelength LEDs is a sum the change of the emission spectra of its components. The accurately tuning wavelengths of the radiation with composition of the active and luminescent layer, almost temperature independent section is formed between closely radiation peaks with nearly same amplitude. Wavelength converter achievable with two luminescent layer also. Separating the absorption and emission layers is necessary in this new structure. This structure results three wavelength photon emission. Our aim is to grow a high efficiency and temperature independent LED for measuring tasks with handheld NIR spectrometers.