完整后设资料纪录
DC 栏位 | 值 | 语言 |
---|---|---|
dc.contributor.author | 陈彦宁 | en_US |
dc.contributor.author | Chen, Yen-Ning | en_US |
dc.contributor.author | 陈振芳 | en_US |
dc.contributor.author | Chen, Jenn-Fang | en_US |
dc.date.accessioned | 2014-12-12T01:49:25Z | - |
dc.date.available | 2014-12-12T01:49:25Z | - |
dc.date.issued | 2010 | en_US |
dc.identifier.uri | http://140.113.39.130/cdrfb3/record/nctu/#GT079821523 | en_US |
dc.identifier.uri | http://hdl.handle.net/11536/47453 | - |
dc.description.abstract | 本论文为探讨含有氮局部局限能阶(N-related localized states)之GaAsN/GaAs量子井(QW)其电子放射特性经照光后的影响以及外加偏压后的萤光特性分析。首先,从电流-电压(I-V)量测中发现,经照光后产生一个额外的电流贡献,此光电流发生的位置恰好对应至C-V曲线中的电容平台,说明此光电流是由GaAsN量子井及氮局部局限能阶所贡献的,藉由选择激发光源能量的探讨,更加确认此光电流的产生来源。 接着,我们利用光电容量测来探讨照光对GaAsN量子井载子放射特性的影响。当光源能量激发QW能阶所产生的电容抬升,是由于照光后电子、电洞不等量地逃离量子井,净电荷暂留于空乏区内,导致空乏区的变化。而在频谱中发现氮局部局限能阶的存在会拉长量子井对光源能量的反应范围。此外,我们也探讨照光对于GaAsN量子井之电子放射速率的影响,在导纳频谱量测(G-F)中,照光后会使电子放射速率明显增加,进一步在变换光源能量的量测中,发现载子放射速率可以被我们调变。藉由光电容频谱量测之结果,再配合萧特基空乏区理论(Schottky depletion theory),我们可以得知由于各种能量之激发光所产生的净电荷量不同,导致空乏区、费米能阶位置的改变,进而影响载子的穿隧放射速率。同时,在深层能阶暂态频谱(DLTS)中,除了观察到照光下电子放射速率增加的现象外,在低温范围还产生一个定值∆C的讯号,经分析此讯号为氮局部局限能阶之载子发生穿隧放射(tunneling emission)所产生。 最后,我们分析在外加偏压下含氮局部局限能阶之GaAsN量子井的萤光特性。于低温时,随逆向偏压的增加,由于QW能阶的穿隧能障较小的缘故,GaAsN量子井萤光强度下降量大于氮局部局限能阶的萤光强度下降量;当温度升高时,氮局部局限能阶萤光强度的下降量转为较大。此结果是由于载子从氮局部局限能阶跃迁至QW的传输现象发生所导致。除此之外,我们由光激发I-V量测发现,氮局部局限能阶贡献光电流的位置随温度升高往较小的逆向偏压移动,此现象也同样为载子传输现象所导致。因此,在GaAsN量子井中,氮局部局限能阶可以产生光电流的贡献并延伸光电容的能量反应范围,并且经由不同光源能量的激发可以调变载子放射速率的快慢,即说明氮局部局限能阶的存在是适合应用于光电元件的设计及其特性调变。 | zh_TW |
dc.description.abstract | This study elucidates the electron emission properties of GaAsN/GaAs quantum well (QW) containing N-related localized states under illumination, and also analyzes the photoluminescence (PL) under applied reverse bias. Initially, according to the current-voltage (I-V) measurement under illumination, two stages of current rise are observed, and the bias range of these current rises corresponds to the voltage of electron escaping from the GaAsN QW and N-related localized states. We apply photocurrent measurement to confirm that the observed current rises are due to the GaAsN QW electron states and N-related localized states. Furthermore, photocapacitance measurement is utilized to investigate the electron emission properties of GaAsN QW containing N-related localized states under illumination. Both GaAsN QW electron states and N-related localized states can contribute the photocapacitance due to the photon-generated electrons escaping into bottom GaAs,which results in a decrease of depletion width of the bottom GaAs. Capacitance-frequency (C-F) measurement was performed to obtain electron emission rate of GaAsN QW electron states under different incident photon energies. According to Schottky depletion theory, the modulation of electron emission rate with photon energy is due to the modulation of Fermi level position. Moreover, we also examine the influence of illuminance on electron emission rate of N-related localized states by deep-level transient spectroscopy (DLTS) measurements. In addition to the increase of electron emission rate of N-related localized states, illumination can induce the tunneling emission of N-related localized states. Finally, we analyze the PL emission under different applied reverse bias. In these measurements, at low temperature, the decrease of PL intensity with increasing reverse bias for the GaAsN QW emission is larger than the decrease of PL intensity for N-related localized states emission, which is attributed to the smaller tunneling barrier for the GaAsN QW electron states. As temperature increases, the carriers on N-related localized states have sufficient thermal energy to transfer to GaAsN QW electron states. Thus, the different PL quenching rate is due to an additional escape path for electrons on the N-related localized states. Furthermore, this carrier transfer phenomenon between GaAsN QW electron states and N-related localized states can be observed from the temperature-dependent I-V measurement under illumination. The bias of the current rise corresponding to N-related localized states is decreased with increasing temperature. This result indicates that the contribution of photo-generated electrons on N-related localized states occurs at the shallower electron states with increasing temperature, and is consistent with the carrier transfer phenomenon for the N-related localized states. Thus, the application of N-related localized states can provide current path for photo-generated electron-hole pairs and extend the energy response range. | en_US |
dc.language.iso | zh_TW | en_US |
dc.subject | 量子井 | zh_TW |
dc.subject | 照光 | zh_TW |
dc.subject | 载子传输 | zh_TW |
dc.subject | quantum well | en_US |
dc.subject | illumination | en_US |
dc.subject | carrier transfer | en_US |
dc.title | 含氮局部局限能阶之GaAsN/GaAs量子井的电子放射特性:照光的影响 | zh_TW |
dc.title | Electron emission properties of GaAsN/GaAs quantum well containing N-related localized states : the influence of illumination | en_US |
dc.type | Thesis | en_US |
dc.contributor.department | 电子物理系所 | zh_TW |
显示于类别: | Thesis |