<link rel="stylesheet" href="styles.cf390c6bfbe7555f.css">

學術出版;;Publications

Permanent URI for this communityhdl:11536/1

收集所有交通大學研究人員與學生個人或團體所發表之各項學術著作，涵蓋期刊論文、教師專書、學位論文等項。;;Collections of Publications of NCTU Researchers and Students Like Journal Papers and Thesis.

Browse

Filters

2016 - 20203

Settings

🏛️國立陽明交通大學機構典藏

Author: search.filters.author.Chang, Shu-WeiSubject: search.filters.subject.light-emitting transistor

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item type:Item,
    Characteristics of Blue GaN/InGaN Quantum-Well Light-Emitting Transistor
    (2020-01-01)
    Lan, Hao-Yu
    ;
    Tseng, I-Chen
    ;
    Lin, Yung-Hsiang
    ;
    Chang, Shu-Wei
    ;
    Wu, Chao-Hsin
    We demonstrate simultaneous electrical and optical modulations of the first GaN/InGaN quantum-well light-emitting transistor (QW-LET) which contains an In-0.15 Ga0.85N QW in the heavily p-doped In-0.05 Ga0.95N base. Unlike GaAs/InGaAs counterparts, the GaN/InGaN QW- LET has a current gain (up to 5) and optical power which increases linearly with the base current. Its emission spectra are centered at a wavelength of 420 nm and barely shift with the current injection, in contrast to the behavior of typical nitride-based LEDs. The unusual features of this device may be related to the tilted band profile induced by the polarization field in the QW and issue of p-type doping.
  • Thumbnail Image
    Item type:Item,
    Carrier lifetime of heavily p-doped base in light-emitting transistors and transistor lasers
    (2019-01-01)
    Hsieh, Chi-Ti
    ;
    Cheng, Pi-Ju
    ;
    Lin, Chih-Hsien
    ;
    Chang, Shu-Wei
    ;
    光電工程學系
    Light-emitting transistor (LET) and transistor laser (TL) can provide the high-speed electrical and optical modulations simultaneously, advancing light-emitting diodes and diode lasers. Still, between experimental data and rate-equation modeling, there are two-order-of-magnitude uncertainties on the carrier lifetimes of quantum wells (QWs) inserted in heavily p-doped bases of these devices. In view of the importance of this timescale on the modulation speed, we provide a comprehensive approach to calculate carrier lifetimes under such circumstances. We model the Hartree potential energy with self-consistent solutions of the Schrodinger's and Poisson's equations. The hole distribution is obtained from real-space density of states through multiband retarded Green functions, taking the outgoing-wave features of hole quasi-bound states into account. We then estimate the carrier lifetimes based on a multiband source-radiation approach including both bound-to-bound and bound-to-continuum components of spontaneous (SP) emissions. Under low surface carrier injections, a large Hartree potential is formed, and the valence band around the QW is strongly tilted. Both bound and quasi-bound valence states are present, and quasi-bound holes may tunnel out of QW and reemerge in the base. The SP spectrum from the QW in the heavily doped base is significantly larger than that from an undoped one due to preexisting holes. At the high injection level, the screening effect significantly reduces the Hartree potential and band bending. We also include the nonradiative Auger recombination to evaluate the total carrier lifetime. Overall carrier lifetimes and small-signal ones are estimated as hundred picoseconds at a doping density of 10(19)cm(-3) and might be even shorter in the case of heavier doping.
  • Thumbnail Image
    Item type:Item,
    The role of optoelectronic feedback on Franz-Keldysh voltage modulation of transistor lasers
    (2016-01-01)
    Chang, Chi-Hsiang
    ;
    Chang, Shu-Wei
    ;
    Wu, Chao-Hsin
    ;
    光電工程學系
    ;
    Department of Photonics
    Possessing both the high-speed characteristics of heterojunction bipolar transistors (HBTs) and enhanced radiative recombination of quantum wells (QWs), the light-emitting transistor (LET) which operates in the regime of spontaneous emissions has achieved up to 4.3 GHz modulation bandwidth. A 40 Gbit/s transmission rate can be even achieved using transistor laser (TL). The transistor laser provides not only the current modulation but also direct voltage-controlled modulation scheme of optical signals via Franz-Keldysh (FK) photon-assisted tunneling effect. In this work, the effect of FK absorption on the voltage modulation of TLs is investigated. In order to analyze the dynamics and optical responses of voltage modulation in TLs, the conventional rate equations relevant to diode lasers (DLs) are first modified to include the FK effect intuitively. The theoretical results of direct-current (DC) and small-signal alternating-current (AC) characteristics of optical responses are both investigated. While the DC characteristics look physical, the intrinsic optical response of TLs under the FK voltage modulation shows an AC enhancement with a 20 dB peak, which however is not observed in experiment. A complete model composed of the intrinsic optical transfer function and an electrical transfer function fed back by optical responses is proposed to explain the behaviors of voltage modulation in TLs. The abnormal AC peak disappears through this optoelectronic feedback. With the electrical response along with FK-included photoncarrier rate equations taken into account, the complete voltage-controlled optical modulation response of TLs is demonstrated.