Optical Absorption Characteristics and Photobleaching Behavior of Trapped Electrons in γ‐Irradiated Alkaline Ice

1971 ◽  
Vol 54 (3) ◽  
pp. 908-914 ◽  
Author(s):  
Hirotomo Hase ◽  
Larry Kevan
Keyword(s):  
Optical Absorption ◽  
Trapped Electrons ◽  
Absorption Characteristics

Improved and tunable optical absorption characteristics of MQW GaAs/AlGaAs nano-scale heterostructure

Optik ◽  
2020 ◽  
Vol 208 ◽  
pp. 164544
Author(s):  
Beena Kumari ◽  
Sandhya Kattayat ◽  
Shalendra Kumar ◽  
Savaş Kaya ◽  
Aavishkar Katti ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Nano Scale ◽  
Absorption Characteristics

Optical Absorption at Digitally and Continuously Graded Indium Gallium Nitride Schottky Barriers

2007 ◽  
Vol 1012 ◽  
Author(s):  
Choudhury Jayant Praharaj
Keyword(s):  
Gallium Nitride ◽  
Optical Absorption ◽  
Schottky Barrier ◽  
Indium Gallium Nitride ◽  
Spectral Response ◽  
Alloy System ◽  
Schottky Barriers ◽  
Material System ◽  
Indium Gallium ◽  
Absorption Characteristics

AbstractWe present numerical calculations of the optical absorption characteristics of graded Indium Gallium Nitride Schottky Barriers, and study their implications for photovoltaic and photodetector applications. We consider the two cases of digital and continuous grading because of their different effects on the collection of photo-generated carriers due to band discontinuities. Composition grading can achieve desired spectral response between the ranges of 0.7 eV and 3.43 eV afforded by the Indium Gallium Nitride alloy system. The presence of spontaneous and piezoelectric polarizations in this material system adds bulk and/or interface bound charges in graded layers. This has a non-trivial effect on the band profile seen by the photo-generated carriers. The layer thicknesses needed for optimal absorption characteristics are well above the theoretical critical thickness limits reported in the literature for abrupt heterojunctions. However, experimental data about critical thicknesses is scarce, especially for graded compositions. Therefore, we calculate the characteristics of the Schottky barrier for the case of spontaneous polarization only and also for the case of both spontaneous and piezoelectric polarization assuming no relaxation. The low or even negative Schottky barrier heights at low Gallium composition necessitates the use of high Gallium composition layers next to the metal, in order to suppress the excessive dark currents

Comparison of photoconductivity and optical absorption spectra of trapped electrons in γ-irradiated 2,2,4-trimethylpentane/2,2-dimethylbutane/2-methyltetrahydrofuran mixture glasses at 77 K

1984 ◽  
Vol 62 (1) ◽  
pp. 64-68 ◽  
Author(s):  
Toyoaki Kimura ◽  
Kazunobu Hirao ◽  
Naoto Okabe ◽  
Kenji Fueki
Keyword(s):  
Absorption Spectrum ◽  
Optical Absorption ◽  
Absorption Spectra ◽  
Electron Mobility ◽  
Optical Absorption Spectrum ◽  
Lower Energy ◽  
Photon Absorption ◽  
Optical Absorption Spectra ◽  
Absorption Process ◽  
Trapped Electrons

Optical absorption and photoconductivity spectra of trapped electrons in -γ-irradiated 2,2,4-trimethylpentane (TMP)/2,2-dimethylbutane (DMB)/2-methyltetrahydrofuran (MTHF) mixture glasses at 77 K have been measured. It is found that the magnitude of the photocurrent increases with decreasing MTHF concentration, which is ascribed to the increase in electron mobility with decreasing MTHF concentration in TMP/DMB/MTHF systems. It is also found that the photoconductivity spectra shift to the lower energy side with decreasing MTHF concentration. Although the photoconductivity spectrum in the neat MTHF system is separated from the corresponding optical absorption spectrum, the spectrum becomes closer to the latter with decreasing MTHF concentration in TMP/DMB/MTHF systems. This result indicates that the extent of bound–free transitions increases relative to bound–bound transitions with decreasing MTHF concentration for the photon absorption process of trapped electrons in TMP/DMB/MTHF systems.

A photoconductivity study of trapped electrons in γ-irradiated hydrocarbon glasses at 77 K

1983 ◽  
Vol 61 (12) ◽  
pp. 2799-2803 ◽  
Author(s):  
Naoto Okabe ◽  
Toyoaki Kimura ◽  
Kenji Fueki
Keyword(s):  
Optical Absorption ◽  
Absorption Spectra ◽  
Conduction Band ◽  
Ground State ◽  
Volume Ratio ◽  
Optical Absorption Spectra ◽  
Trapped Electrons ◽  
Trapped Electron

Photoconductivity spectra of trapped electrons in γ-irradiated 3-methylpentane, 2-methylpentane, 3-methylheptane, and 3-methylpentane–methylcyclohexane (1:9 volume ratio) glasses at 77 K were measured. From the comparison of photoconductivity and optical absorption spectra in these systems we have obtained relative values of quantum efficiencies for a trapped electron in the ground state to be excited to the conduction band by photo-induced transition. For electrons stably trapped, we have measured the ranges of trap depths from the shallowest to the deepest in these systems.

Optical absorption characteristics of hydroxyl radicals in phosphorus-containing silica glass

1977 ◽  
Vol 13 (2) ◽  
pp. 55 ◽  
Author(s):  
Yoh Mita ◽  
Shigeo Matsushita ◽  
Tomoo Yanase ◽  
Hidenori Nomura
Keyword(s):  
Optical Absorption ◽  
Hydroxyl Radicals ◽  
Silica Glass ◽  
Phosphorus Containing ◽  
Absorption Characteristics

Dynamic Studies of the Optical Absorption Associated with Trapped Electrons

1970 ◽  
Vol 2 (12) ◽  
pp. 4988-4994 ◽  
Author(s):  
R. J. Bieringer ◽  
C. G. Montgomery
Keyword(s):  
Optical Absorption ◽  
Trapped Electrons ◽  
Dynamic Studies
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