- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Raman spectroscopic determination of hole concentration in undoped GaAsBi
摘要： Raman spectra of the undoped GaAs1-xBix (0<x<0.037) grown on GaAs by molecular beam epitaxy were investigated. With an increase of Bi component, we find that the longitudinal optical phonon-hole-plasmon-coupled (LOPC) mode first appears in the vicinity of the unscreened longitudinal optical (ULO) phonon frequency, and then shifts towards near the transverse optical (TO) phonon frequency. A new vibrational modes (~287 cm-1) between the TO and the ULO phonons was verified by use of low temperature polarized Raman measurement and the corresponding scattering intensities are found to be linearly proportional to the composition of Bi in GaAsBi. The hole concentrations determined by using the LOPC/ULO Raman intensities ratio increase from ~6.5×1016 to ~2.8×1017 cm -3 with Bi content and the measured results are in agreement with Hall measurements. Furthermore, the influence of excitation laser power on the estimation of the hole densities is discussed with the help of power dependent Raman spectroscopy.
关键词： Hall measurements,LO-phonon-plasmon–modes,Raman Spectroscopy,GaAsBi,Hole density
更新于2025-09-23 15:21:21
-
Sensors, Circuits and Instrumentation Systems (2018) || Investigation of Optoelectronic Properties of Amorphous Silicon Germanium Photodetectors
摘要： Cost consideration of the development of electronic devices is one of prime importance. One simple approach to lower the cost of production of photovoltaic and detectors is by using low cost materials such as amorphous silicon and germanium. These two semiconductors have different optoelectronic properties, such as energy gap, photoconductivity and absorption coefficient. The use of an alloy from the mixing of silicon with certain percentages of germanium would produce photodetectors with improved electronic characteristics and photoconductivity. A number of a-SiGe alloy thin films with different quantities of germanium have been fabricated using thermal vacuum evaporation technique. Conduction mechanism and activation energy of the prepared samples had been calculated and analyzed. The I–V characteristics, the photogenerated current and detectivity of these samples are subjected to measurement and discussion. Hall measurements are also conducted so to calculate the Hall I–V characteristics, Hall mobility, carrier concentration and type identification of the samples.
关键词： Amorphous silicon germanium photodetector,photoconductivity,detectivity,Hall measurements,activation energy,conduction mechanism
更新于2025-09-16 10:30:52
-
AIP Conference Proceedings [AIP Publishing LLC OPTOELECTRONIC MATERIALS AND THIN FILMS: OMTAT 2013 - Kochi, Kerala, India (3–5 January 2013)] - Annealing effects on the structural and electrical properties of pulsed laser deposited BaPbO3 thin films
摘要： Conductive pervoskite BaPbO3 (BPO) ?lms as potential electrodes for ferroelectric / tuneable applications were prepared by pulsed laser deposition technique at 6000C and at 0.1 mbar oxygen partial pressure on fused silica substrates. The structural and electrical properties of the ?lms showed a dependence on annealing temperatures and the high oxygen ambient. XRD and standard four probe method with Hall setup were employed to investigate the dependence of growth conditions on crystal structure, resistivity and the carrier concentration on annealing the BPO thin ?lms. The surface topography was analysed by AFM. The unannealed as deposited ?lms showed the least resistivity of 1.6 x 10?2 ohm cm and a bandgap of 4.1eV.
关键词： BPO,PLD,Hall measurements
更新于2025-09-16 10:30:52