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.
| Identifer | oai:union.ndltd.org:METU/oai:etd.lib.metu.edu.tr:http://etd.lib.metu.edu.tr/upload/12612718/index.pdf |
| Date | 01 December 2010 |
| Creators | Anutgan, Mustafa |
| Contributors | Katircioglu, Bayram |
| Publisher | METU |
| Source Sets | Middle East Technical Univ. |
| Language | English |
| Detected Language | English |
| Type | Ph.D. Thesis |
| Format | text/pdf |
| Rights | To liberate the content for public access |
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