Nanokristal silisyum tabanlı görünür ışık yayan pin diyotlar.

The production of low cost, large area display systems requires a light emitting material compatible with the standard silicon (Si) based complementary metal oxide semiconductor (CMOS) technology. The crystalline bulk Si is an indirect band semiconductor with very poor optical properties. On the other hand, hydrogenated amorphous Si (a-Si:H) based wide gap alloys exhibit strong visible photoluminescence (PL) at room temperature, owing to the release of the momentum conservation law. Still, the electroluminescence (EL) intensity from the diodes based on these alloys is weak due to the limitation of the current transport by the localized states. In the frame of this work, first, the luminescent properties of amorphous silicon nitride (a-SiNx:H) thin films grown in a plasma enhanced chemical vapor deposition (PECVD) system were analyzed with respect to the nitrogen content. Then, the doping effciency of p- and n-type hydrogenated nanocrystalline Si (nc-Si:H) films was optimized via adjusting the deposition conditions. Next, the junction quality of these doped layers was checked and further improved in a homojunction pin diode. Heterojunction pin light emitting diodes (LEDs) were fabricated with a-SiNx:H as the luminescent active layer. The EL effciency of the fresh diodes was very low, as expected. As a solution, the diodes were electro-formed under high electric field leading to nanocrystallization accompanied by a strong visible light emission from the whole diode area. The current-voltage (I-V) and EL properties of these transformed diodes were investigated in detail.Ph.D. - Doctoral Progra