固体物理导论-优秀PPT.ppt
Great Experimentalist :/dsc.discovery /tv/mythbusters/:/verycd /topics/61524/What we can learn from them:The method/design of experiments Todays OutlinePhoton(光子)Phonon(声子)Lets talk about LightGod said,Let there be light;and there was lightFor a physicist 詹姆斯詹姆斯克拉克克拉克麦克斯韦麦克斯韦 James Clerk Maxwell 18311879从牛顿到爱因斯坦这一整个阶段中最宏大的理论物理学家 建立了麦克斯韦方程组 创立了经典电磁学 预言了电磁波的存在 提出了光的电磁说运用数学工具分析物理问题和精确地表述科学思想的大师Light is Electromagnetic Wave“麦克斯韦在潜心探讨了法拉第关于电磁学方面的新理论和思想之后,坚信法拉第的新理论包含着真理。于是他抱着给法拉第的理论“供应数学方法基础”的愿望,决心把法拉第的天才思想以清晰精确的数学形式表示出来。”1888年德国物理学家赫兹用试验验证了电磁波的存在Solar SpectrumPhotoelectric EffectWork Function(电子溢出功)Evacuum EF,work function波粒二象性(wave-particle duality)Radiation Quantization Quantized Radiation:Photon h:普朗克常数(6.626 x 1034 Js)红光:650nm,1.97 eVE=h=c/Photo-excitation/Radiation excitation Radiative/Non-radiative RecombinationPhoto-Electron interactionPhoto generationFundamentals for photo detectors and solar cells Radiative recombinationFundamentals for Light Emitting Diodes(LED)and Lasers Break!PhononQuantized lattice vibrationAtomic vibration at room temperature:1Vibration has different modes:Phonon modesEnergy of phonons:E=hDensity of State function for electronsDispersion Relation:density of phonon modes Different phonon modesLA:longitudinal acoustic TA:Transverse acousticLO:longitudinal optical TO:Transverse optical E=hPhonon-Photon interactionEmission of photon,thermal radiationAbsorption of photon,heating of lattice Theories not clearPhonon-Electron interactionPhonon scattering of carriers 精品课件精品课件!精品课件精品课件!Conservation of energy and momentum Photonlarge energy,very litter momentumRoom temperature Phonon:large momentum,little energy Electronlarge energy,large momentum