Three-Terminal Heterojunction Phototransistor and Optoelectronic-Circuit Application

• Main Authors: An-Hung Lin, 林安宏
• Other Authors: Wen-Shiung Lour
• Format: Others
• Language: en_US
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/73292832431897610217

碩士 === 國立臺灣海洋大學 === 電機工程學系 === 92 === In this thesis, the model and characteristics of Heterojunction PhotoTransistor (HPT) is investigated. Both Gummel-plot and common-emitter configurations are employed to characterize HPT’s performances and to clearly demonstrate what difference between a voltage-biased and a current-biased HPT. The performances of the voltage- and current-source biased HPTs were also compared to the results from a newly proposed HPT model and related circuit with good agreement found. Although an independent voltage source pushes HBT’s operating point to a higher current level where the dc current gain is larger, however, the photocurrent generated within B-C region gives very little contribution to final collector current. The optical gain obtained from high-voltage-source biased HPT is even smaller than that of a HPT with a floating base. We will fabricate IP- and NP-HPTs and measure them make us device performances include of relations of layer to layer reflection. Furthermore, Single- and double-emitter heterojunction phototransistors with the same total emitter area have been fabricated and qualitatively investigated successfully for theoretical bases of chapter 2,3 and 4. The double emitters in two kinds of DE-HPTs are designed to have area ratio of 1:1 and 1:2, respectively. Both a positive and a negative voltage applied to the second emitter can control and enhance the collector photocurrent that formed a new three-terminal phototransistor. And we probe into optical gain and the second emitter operation voltage under different area ratios, so we could use these performances to develop the optical logic circuits.