高电场下In_（0．53）Ga_（0．47）As／In_（0．52）Al_（0．

DETERMINAtION OF HOMO-AND INHOMOGENEOUS BROADENING OF ELECTSO-TRANSMITTHNCE SPECTRA OF 11h EXCITON TRANSITION IN In_(0.53) Ga_(0.47)As/In_(0.52)Al_(0.48)As WIDE WELL AT HIGH ELECTRIC FIELD

研究在外加电场０～５０ｋＶ／ｃｍ范围内，Ｉｎ０．５３Ｇａ０．４７Ａｓ／Ｉｎ０．５２Ａｌ０．４８ＡＳ宽量子阱电透射光谱中１１ｈ激子跃迁的谱线宽度（ＦＷＨＭ）．它可分解为由温度及界面粗糙度引起的非均匀展宽（高斯型）和由外场引起的均匀展宽（劳伦兹型）．用线性叠加的近似公式代替高斯和劳伦兹方程的卷积，再与实验光谱拟合．谱线总宽度、高斯展宽成份及线性叠加系数η均作为拟合参数得到，从而可得劳伦兹展宽．将与外场的关系曲线与理论作比较，在数量级上一致．

The linewidths (FWHM) of 11h exciton transition of in0.53Ga0.47As/In0.52A10.48As SQWs electrotransmittance spectra in the electric field range between 0 and 50kV/cm were investigated. The linewidth can be decomposed illto two compo nents: inhomogeneous (Gaussian profile) when temperature or interface roughness are dominated and homogeneous (Lorentzian profile) when field ionization are important.An approximation to the convolution of a Lorentzian with a Gaussian function was used by taking a linear superposition of them in fitting electrotransmittance spectra.The parameters in (Gaussian broadening), (total FWHM) and the fraction η of the lineax superposition were obtained from the fitting. Then (Lorentzian) was found.The relationship between (Lorentzian) and electric field is ill order-of-magnitudeagreement with the direct theoretical calculation of field ionization for two--dimensionalexcitons.