| Summary: | 碩士 === 長庚大學 === 光電工程研究所 === 98 === This work studies the interference patterns surface and edge spectra of AlGaInP and nitride light-emitting diodes device.
By measuring surface and backside spectra of nitride sample, we discover the phenomenon of interference patterns spectra does not cause by filtering effect. The interference is attributed to the modulation of the spontaneous emission rather than the filtering effect of an optical thin film. We also discover the spontaneous emission rates are controllable. The radiation rate can be tune through the change of the optical field distribution. We cannot utilize the EM wave solution of Maxwell equation to describe the spontaneous emissions. Therefore, by measuring the photocurrent and emission spectra of AlGalnP device know the structural corresponding to the absorption and emission rate. At the same time, we also simulate the optical field distribution of EM wave. When the quantum well electron-hole pair dipole formed interaction strongly with the optical field, the absorption rate of EM waves are enhanced, the emission rate are enhanced too. On the other hand, the emission rates decrease follow the optical fields reduce. In conclusion, we know the modulation of emission spectra is the interference patterns.
We know the attribution of surface interference spectra and base on the theorem to measure the spectra of vary angle of nitride sample. We find the edge spectra of nitride are attributed to the surface high angle equivalent interference patterns. And the interference patterns cycle increase with the emission angle. The result corresponds with the simulation and also demonstrates the optical resonator model
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