多量子阱GaAs／Al_xGa_（1－x）As电极的瞬态光电流行为  

Transient Photocurrent Behavior of Multiple Quantum Well GaAs/Al_xGa_(1-x)As Electrode

作　　者：刘尧[1] 肖绪瑞[1] 林原[1] 曾一平[1] 孙殿照[1] 郑海群[1] 

机构地区：[1]中国科学院感光化学所,中国科学院半导体研究所

出　　处：《电化学》1995年第1期21-24,共4页Journal of Electrochemistry

基　　金：国家自然科学基金

摘　　要：多量子阱ＧａＡｓ／Ａｌ＿ｘＧａ＿（１－ｘ）Ａｓ电极的瞬态光电流行为刘尧，肖绪瑞，林原（中国科学院感光化学所，北京１００１０１）曾一平，孙殿照，郑海群（中国科学院半导体研究所，北京１０００８３）由于半导体超晶格（量子阱）能带的量子化，使其具有许多完全不...Transient photocurrents induced by short light pulses at lattice-matched multiplequantum well(MQW)GaAs/Al_(0.3)Ga_(0.7)As electredes were studied in the 1 ×10￣(-2)mol·dm￣(-3)ferrocene([Fc￣0]/[Fc)￣+]=9/1)-0.1 mol·dm￣(-3)tetrabutylammonium tetrafluoroborate acetonitrile solutionin order to examine the relaxation photoprocesses and to evaluate kinetic parameters of superlattice electrodes. GaAs/Al_(0.3)Ca_(0. 7)As MQW electrode consisting of 10 periods with each of GaAs well(5.3nm)and Al_(0. 3)Ga_(0. 7)As barrier(10nm)showed two pronounced and well-resolved peak structures located at 1.503 eV and 1.699 eV in the photocurrent spectrum,corresponding to the theoretical allowedexcitonic transitions(Δn=0) for heavy holes(H11,H22)in the quantum well respectively. Transient photocurrent spectra were measured by a monochromatic light pulse with 7 μs pulsewidth and 9 nJ·cm￣(-2) of energy at λ=800 nm preduced by a pulsed xenon lamp via amonochromator,and analyzed by Pade boplace transform method. Photocurrent transients werecharacterized by a rapid decays following by a slow exponent at the electrode potential varying from-2.3 V to 0 V vs SCE,and exhibited typical I-V behaviours of n-type semiconductor.Dualexponential transient photocurrent decay were demonstrated by the two segments with different slope inthe relations of normalized logarithm of photocurrent response and decay time, representing twoprocesses-RC(fast)and surface recombination(slow).By fitting the transient decay to the dualexponent function of the form:I(t)=A_1exp(-t/τ_2)+A_2exp(-t/τ_2),where t is the decay time,A_1,A_2 and τ_1,τ_2 correspond to the amplitudes and time constants of the fast and slow decaysrespectively。The kinetic parameters such as the normalized steady state photocurrent(I_s/G_0 )andsurface state lifetime(T_s) were determined in frequency domain. Both of the I_s/G_0 defined as therelative ratio of photogenerated carrier transferred from the electrode to electrolyte and the T_s reflectedthe rate of the surface recombi

关 键 词：量子阱 超晶格 半导体 MQW电极 

分 类 号：O646.54[理学—物理化学]