The Investigation of Quantum Effects of Band-Edge Modulated Nano-Structure Noncrystalline

带边调制纳米结构非晶的量子效应研究

• 批准号: 10650023
• 负责人: MORIGAKI Kazuo
• 金额: $ 2.24万
• 依托单位: Hiroshima Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10650023/
• 关键词: Noncrystalline; Amorphous; Semiconductors; Nanostructure; Quantum effect; Band-edge modulation

The band-edge modulated a-Si, N : H films are used in this study as band-edge modulated nano--structure-noncrystalline semiconductors, which are fabricated by spatially modulating nitrogen content along a direction perpendicular to the deposited film. In this film, the bottom of conduction band and the top of valence band are spatially modulated along this direction, because the band gap is varied by nitrogen content. The optical gap energy has been confirmed to be varied by the modulation period of the film. This can be accounted for in terms of one-dimensional harmonic oscillator potential model giving the separation of the lowest quantized levels of both bands as a function of the modulation period.In this study, we have attempted observations of optical transitions between the quantized levels, using the techniques of optical absorption and photoconductivity. We have developed the optical system making enable to observe these transitions. The experiments are going on down to 11K fo … More r this purpose.The defects states and their quantum effects of the band-edge modulated a-Si, N : H films have been investigated using the electron spin resonance (ESR) technique. The observed g-values of silicon dangling bonds range between 2.0031-2.0039 in the films of modulation periods of 21-100Å. No dependence of the g-value on the modulation period has been observed. From the g-values, the magnetic centres responsible for ESR are identified by silicon dangling bonds having three back-bonds with nitrogen and having two back-bonds with nitrogen and one back-bond with silicon. These dangling bonds exist in the nitrogen-rich region. They are deep centres so that the g-value is not affected by quantum effect. The spin density is increased with decreasing the modulation period because the nitrogen-rich region becomes more disordered.The luminescence of the band-edge modulated films arises from radiative recombination of singlet excitons, triplet excitons and electron-hole pairs. The excitons are found to be more stabilized by the confinement effect of modulated potentials. Less

本研究中使用的带边调制的a-Si，N：H薄膜作为带边调制的纳米结构非晶半导体，它是通过沿着垂直于沉积薄膜的方向空间调制氮含量而制备的。在该薄膜中，导带底和价带顶沿着该方向空间调制，因为带隙随氮含量而变化。已被证实的光学带隙能量是由薄膜的调制周期的变化。这可以解释为一维谐振子势模型，给出了两个带的最低量子化能级的分离作为调制周期的函数，在这项研究中，我们试图观察量子化能级之间的光学跃迁，使用光学吸收和光电导技术。我们已经开发了光学系统，使能够观察到这些转变。实验正在进行到11 K， ...更多信息 利用电子自旋共振（ESR）技术研究了带边调制a-Si，N：H薄膜的缺陷态及其量子效应。在调制周期为21-100 μ m的薄膜中，观察到的硅悬挂键g值在2.0031-2.0039之间。没有观察到g值对调制周期的依赖性。根据g值，负责ESR的磁性中心通过具有三个与氮的背键以及具有两个与氮的背键和一个与硅的背键的硅悬挂键来识别。这些悬挂键存在于富氮区。它们是深中心，因此g值不受量子效应的影响。自旋密度随着调制周期的减小而增加，这是由于富氮区变得更加无序，带边调制薄膜的发光来自于单重态激子、三重态激子和电子空穴对的辐射复合。激子被发现是更稳定的调制电位的限制效应。少

项目成果

K. Morigaki: "Physics of Amorphous Semiconductors"World Scientific, Singapore and Imperial College Press, London. 418 (1999)

K. Morigaki：“非晶半导体物理学”世界科学出版社，新加坡和伦敦帝国理工学院出版社。

C.Ogihara,K.Morigaki他: "Lifetime Distribution of PLunder pulsed excitation in hydrogenated amorphous silicon based films"Journal of Noncrystalline Solids. (印刷中). (2000)

C. Ogihara、K. Morigaki 等人：“氢化非晶硅基薄膜中脉冲激励下的寿命分布”非晶固体杂志（2000 年出版）。

C. Ogihara et al.: "Lifetime distribution of PL under pulsed excitation in hydrogenated amorphous silicon based films"Journal of Noncristalline Solids. (in press). (2000)

C. Ogihara 等人：“氢化非晶硅基薄膜中脉冲激发下 PL 的寿命分布”非晶固体杂志。

C. Ogihara, K. Morigaki 他: "Lifetime Distribution of Plunder pulsed excitation in hydrogenated amorphous silicon based films"Journal of Noncrystalline Solids. (印刷中). (2000)

C. Ogihara、K. Morigaki 等人：“氢化非晶硅基薄膜中掠夺脉冲激发的寿命分布”非晶固体杂志（2000 年出版）。

K.Morigaki: "Physics of Amorphous Semiconductors"World Scientific,Singapore and Imperial College Press,London. 418 (1999)

K.Morigaki：“非晶半导体物理学”世界科学出版社，新加坡和帝国理工学院出版社，伦敦。