非晶矽/石墨烯光二極體之研究

Research on The Amorphous Silicon/Graphene Junction Photodiode

張浩倫(Chang, Hao Lun)

指導教授 ： 徐永珍

國立清華大學/電機資訊學院/電子工程研究所/碩士(2015年)

摘要

本研究是利用以石墨烯與非晶矽接成的二極體接面形成影像感測器的感光元件，調整非晶矽的厚度與摻雜情況，測試在不同的光強下觀察光偵測器的特性。
此石墨烯是利用APCVD成長，調整通入成長氣體的時間，改變石墨烯的品質；非晶矽是利用PECVD成長，調整成長非晶矽的厚度與摻雜，改變非晶矽吸收光線波段，達到更好的吸收效率。
實際完成之感光元件以單層石墨烯分別與300奈米本質非晶矽、270奈米本質非晶矽搭配30奈米N型態非晶矽、和170奈米本質非晶矽搭配30奈米N型態非晶矽之接面為主，除了此主要接面外，並量測元件中所有的接面，包括金電極與石墨烯、鋁電極與非晶矽、和探針與非晶矽等接面，以便排除所有可能影響量測結果的因素，進而得到準確的石墨烯與非晶矽接面光偵測器的特性。

關鍵字

石墨烯 ； 非晶矽 ； 光二極體

並列摘要

This study made use of graphene and amorphous silicon in order to fabricate a heterojunction photodetector, in which controlling the thickness and doping properties of the amorphous silicon film allows for fine-tuning of the photodetector properties. The device response to different light intensities were characterized.
Graphene was grown via APCVD using a gaseous carbon source in an Argon atmosphere, in which controlling the carrier gas flow and growth time has a direct impact on the quality of the as-grown graphene film. On the other hand, the amorphous silicon layer was grown using PECVD under different conditions. For this film, changes in the doping condition allow for different wavelength light absorption properties, in order to achieve an optimum light absorption.
The fabricated photodetector mainly consists of a junction between a single monolayer graphene sheet and a 300nm thick intrinsic amorphous silicon layer, a 270nm thick intrinsic amorphous silicon layer plus a 30nm N-doped amorphous silicon thin film, or a 170nm thick intrinsic amorphous silicon layer plus a 30nm N-doped amorphous silicon layer. At both sides of the junction, ohmic contacts are deposited. In order to avoid undesired influences from the contacts and to quantify their influence, the conduction property of the contacts, which include the junctions between graphene and gold, aluminum and amorphous silicon, as well as probe needles and amorphous silicon, is characterized. Thus the properties of the graphene and amorphous silicon junction can be correctly derived from the measurements.

並列關鍵字

graphene ； amorphous silicon ； photodiode

參考文獻

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