Nghiên cứu một số cơ chế tán xạ ảnh hưởng đến thời gian sống vận chuyển và thời gian sống lượng tử trong các hệ hai chiều

ĐẠI HỌC QUỐC GIA HÀ NỘI TRƯỜNG ĐẠI HỌC KHOA HỌC TỰ NHIÊN  Trần Thị Hải NGHIÊN CỨU MỘT SỐ CƠ CHẾ TÁN XẠ ẢNH HƯỞNG ĐẾN THỜI GIAN SỐNG VẬN CHUYỂN VÀ THỜI GIAN SỐNG LƯỢNG TỬ TRONG CÁC HỆ HAI CHIỀU LUẬN ÁN TIẾN SĨ VẬT LÝ Hà Nội – Năm 2010 Mưc lưc Líi cam oan Líi cÊm ỡn Mửc lửc Danh mửc cĂc kỵ hiằu v ch vit tt Danh mửc cĂc hnh v, ỗ th M— U C CCÌCH T NX CÌB N NHH×—NG N TH˝I GIAN H˙I PHÖC CÕA H T T I 1.1 C¡c kh¡i ni»m ban ƒu 1.1.1 1.1.2 1.1.3 1.2 C¡c cì ch‚ t¡n x⁄ 1.2.1 1.2.2 1.2.3 1.2.4 HI N T×ĐNG V N CHUY N CÕA H T T I TRONG GI NG L×ĐNG TÛ PHA T P MáT PH A 2.1 Ging lữổng tò vuổng g 2.1.1 2.1.2 Mỉ h…nh gi‚ng 2.1.3 2.1.4 C¡c cì ch‚ t¡n x⁄ c 2.1.5 nh h÷ðng cıa hi» 2.2 K‚t qu£ t‰nh to¡n thíi gi t£i mỉ h…nh pha HI N T×ĐNG V N CHUY N CÕA H T T I TRONG GI NG L×ĐNG TÛ PHA T P ¨I XÙNG HAI PH A 96 3.1 Mæ h…nh gi‚ng lữổng tò pha i xứng hai pha 97 3.1.1 H m sâng bi‚n ph¥n v Th‚ Hartree cho tr÷íng hỉp pha t⁄p Łi xøng 99 3.1.2 3.1.3 3.2 nh h÷ðng cıa hi»u øng u chån låc hai ph‰a l¶n t‰ 3.2.1 3.2.2 3.2.3 3.2.4 3.2.5 3.2.6 X C NH áCL PC CTHAMSăB M T V 4.1 Vai trặ ca v 4.2 Nhng khõ khôn ca cĂ nh v 4.3 lỵ mt cĂch c lp Thới gian hỗi phửc ca h quan dữợi Ênh hững ca 4.4 Ph÷ìng ph¡p x¡c ành ºc KTLUN DANH MƯC C C C˘NG TR NH KHOA H¯C T ILI UTHAMKH O PHệ LệC Danh mửc cĂc kỵ hiằu v chœ vi‚t t›t SR := º nh¡m b• m°t DP := Th‚ bi‚n d⁄ng khỵp sai: RI := T⁄p bà ion hâa: AP := Phonon ¥m AD := Khỉng tr“t tỹ hổp kim bĂn dÔn: QW s := Ging lữổng tò: := Thới gian hỗi phửc ca ht tÊi: t := Thíi gian sŁng v“n chuy”n: q := Thíi gian sng lữổng tò: := linh ng ca ht tÊi: := dÔn iằn: L := Bã rng ging lữổng tò: ps := Nỗng ht tÊi: m := Khi l÷ỉng hi»u dưng cıa h⁄t t£i: Q := H» sŁ n¥ng cao º linh := H m sâng bao: EF := Nông lữổng Fermi: kF := S sõng Fermi: 1S := Pha t⁄p mºt ph‰a: 2S := Pha t⁄p hai ph‰a: ACF := H m tü t÷ìng quan: ºng cıa h⁄t t£i: Danh möc c¡c h…nh v‡, H…nh 1.1 H…nh 1.2 H…nh 2.1 H…nh 2.2 H…nh 2.3 H…nh 2.4(a) H…nh 2.4(b) H…nh 2.5(a) H…nh 2.5(b) H…nh 2.6(a) H…nh 2.6(b) H…nh 2.7 H…nh 2.8(a) H…nh 2.8(b) H…nh 2.9 H…nh 2.10 H…nh 2.11 H…nh 2.12 H…nh 3.1 H…nh 3.2(a) H…nh 3.2(b) Hnh 3.3 ỗ th Hnh 3.4 Hnh 3.5 Hnh 3.6(a) H…nh 3.6(b) H…nh 3.7 H…nh 3.8 H…nh 3.9 H…nh 3.10 H…nh 3.11 H…nh 3.12 H…nh 3.13 H…nh 3.14 H…nh 4.1 H…nh 4.2 H…nh 4.3 H…nh 4.4 M— U Lỵ chồn ãti Nôm 1957 Schrieffer [75]  ÷a nh“n ành r‹ng: c¡c i»n tß bà giam h Âm mt ging th hàp lợp Êo ca mt chĐt bĂn dÔn s cõ ứng xò khổng giŁng nh÷ kh‰ cŒ i”n ” ìn gi£n x†t h» iằn tò ging th vuổng gõc sƠu vổ hn câ hai th nh gi‚ng vng gâc vỵi trưc z Vợi ging hàp, chuyn ng theo phữỡng z b lữổng tò hõa Chuyn ng ca hằ iằn tò tr th nh: chuy”n ºng tü m°t phflng (x; y) v b lữổng tò hõa theo phữỡng z, cõ th nõi chuyn ng b õng theo phữỡng n y Chóng ta câ h» chu'n chi•u (Quasi-two dimensional system) H» thøc t¡n s›c câ d⁄ng E ð = En + ~2 2 (k + k ); x y 2m ¥y kx v ky l c¡c th nh phƒn v†ctì sâng chuy”n ºng song song vỵi ti‚p biản, cặn En l cĂc mức nông lữổng xuĐt hiằn iằn tò b giam hÂm ging hàp [4] Ph nông lữổng ca iằn tò tr nản giĂn on dồc theo cĂc hữợng tồa b giợi hn, õ l c trững chung ca ht dÔn cĂc cĐu trúc cĂc hằ thĐp chiãu iãu n y cho thĐy cĂc hằ cõ cĐu trúc nano v thĐp chiãu cĂc quy lut lữổng tò bt u cõ hiằu lỹc, trữợc ht thổng qua bin i c trững ph nông lữổng Cổng trnh thỹc nghiằm tiản phong ca Esaki v Tsu (1970) vã ging lữổng tò  u cho mt hữợng mợi ca vt lỵ nghiản cứu cĂc tnh chĐt ca cĂc hằ iằn tò hai chiãu CĂc nghiản cøu n y âng vai trỈ quan trång vi»c hnh th nh v phĂt trin ca vt lỵ v cổng nghằ cĂc cĐu trúc nano Thới gian gn Ơy vi»c t…m ki‚m v nghi¶n cøu c¡c v“t li»u cho c¡c linh ki»n i»n tß ng y mºt nhä hìn vã kch thữợc, tiảu hao t nông lữổng v cõ tŁc º chuy”n m⁄ch nhanh ng y c ng trð th nh 10 T i li»u tham kh£o [1] Antoszewski J., Gracey M., Dell J M., Faraone L., Fisher T A., Paris G., Wu Y F and Mishra U K (2000), Scattering mechanisms limiting two-dimensional electron gas mobility in Al0:25Ga0:75N=GaN modulation-doped field-effect transistors", J Appl Phys Vol 87, 3900 [2] Ando T and Uemura Y (1974), Theory of Quantum Transport in a Two-Dimensional Electron System under Magnetic Fields I Characteristics of Level Broadening and Transport under Strong Fields", J Phys Soc Jpn Vol 36, pp 959-967 [3] Ando T (1982), Self-Consistent Results for a GaAs=Al xGa1 xAs Heterojunction I Subband Structure and Light-Scattering Spectra ", J Phys Soc Jpn Vol 51, 3893; Self-Consistent Results for a GaAs=AlxGa1 xAs Heterojunciton II Low Temperature Mobility", J Phys Soc Jpn Vol 51, 3900 [4] Ando T., Fowler A B., and Stern F (1982), Electronic properties of two-dimensional systems", Rev Mod Phys Vol 54, 437 [5] Bastard G (1988), Wave Mechanics Applied to Semiconductor Hererostructures, Les Editions de Physique, Paris 137 [6] Balsley I (1966), Influence of Uniaxial Stress on the Indirect Ab-sorption Edge in Si and Ge", Phys Rev Vol 143, 636 [7] Balkan N., Gupta R., Cankurtaran M., Celik H., Bayrakli A., Tiras E and Arikan M C (1997), Well-width dependence of interface roughness scattering in GaAs=Ga1 xAlxAs quantum wells", Superlattices Microstruct Vol 22 (9), pp 263-271 [8] Bir G L and Pikus G E (1974), Symmetry and Strain Induced Effects in Semiconductors, Wiley, New York [9] Belford R E., Guo B P., Xu Q., Sood S., Thrift A A., Teren A., Acosta A., Bosworth L A and Zell J S (2006), Strain enhanced p-type metal oxide semiconductor field effect transistors", J Appl Phys Vol 100, 064903 [10] Celik H., Cankurtaran M., Bayrakli A., Tiras E and Balkan N (1997), Well-width dependence of the in-plane effective mass and quantum lifetime of electrons in multiple quantum wells", Semicon Sci Technol Vol 12, 389-395 [11] Campman K L., Schmidt H., Imamoglu A and Gossard A C (1996), Interface roughness and alloy-disorder scattering contribu-tions to intersubband transition linewidths", Appl Phys Lett Vol 69, 2554 [12] Cankurtaran M., Celik H., Tiras E., Bayrakli A and Balkan N (1998), Well-width dependence of warm electron relaxation and interface roughness scattering in GaAs=Ga xAlxAs multiple quan-tum wells", Phys Status Solidi B Vol 207, 139 138 [13] Coleridge P T., Stoner R and Fletcher R (1989), Low-field transport coefficients in GaAs=Ga1 Phys Status Solidi B Vol 39, 1120 [14] xAlxAs heterostructures", Das Sarma S and Stern F (1985), Single-particle relaxation time versus scattering time in an impure electron gas", Physics Review B Vol 32(12), pp 8442-8444 [15] Dulub O., Diebold U and Kresse G (2003), Competing stabiliza-tion mechanism for the polar ZnO(0001)-Zn surface", Physics Re-view B Vol 68, 245409 [16] Dingle R., Stormer H L., Gossard A C and Wiegmann W (1978), Electron mobilities in modulation-doped semiconductor heterojunction superlattices", Appl Phys Lett Vol 33, 665 [17] Dziekan T., Zahn P., Meded V and Mirbt S (2007), Theoretical calculations of mobility enhancement in strained silicon", Physics Review B Vol 75, pp 195213-195220 [18] Datta (1995), Electronic transport in mesoscopic systems, Cambridge University Press [19] S Emeleus C J.,Whall T E., Smith D W., Kubirak R A., Parker E H C., Kearney M J (1993), Scattering mechanisms affecting hole transport in remote-doped Si/SiGe heterostructures", J Appl Phys Vol 73, 3852 [20] Enderlein R and Horing N J M (1997), Fundamentals of Semiconductor Physics and Devices, World Scientific, Singapore [21] Elhamri S., Saxler A., Mitchel W.C., Elsass C R., Smorchkova I P., Heying B., Haus E., Fini P., Ibbetson J P., Keller S., Petroff 139 P M., DenBaars S P., Mishra U K., Speck J S (2000), Persis-tent photoconductivity study in a high mobility AlGaN/GaN het-erostructure", J Appl Phys Vol 88, 11 [22] Fischetti M V and Gamiz S E (1996), Band structure, deformation potentials, and carrier mobility in strained Si, Ge, and SiGe alloys", J Appl Phys Vol 80, 2234 [23] Fischetti M V., Gamiz F., and Hansch W (2002), On the enhanced electron mobility in strained-silicon inversion layers", J Appl Phys Vol 92, 7320 [24] Feenstra R M and Lutz M A (1995), Scattering from strain vari-ations in high-mobility Si/ SiGe heterostructures", J Appl Phys Vol 78, 6091 [25] Feenstra R M and Lutz M A., Stern F., Ismail K., Mooney P M., LeGoues F K., Stanis C., Chu J O and Meyerson B S (1995), Scattering from strain variations in high-mobility Si/ SiGe heterostructures", J Vac Sci Technol B Vol 13, 1608 [26] Gold A (1987), Electronic transport properties of twodimensional electron gas in a silicon quantum-well structure at low temperature", Phys Rev B 35, 723 [27] Gold A (2008), Interface-roughness parameters in InAs quantum wells determined from mobility", J Appl Phys 103, 043718 [28] Gold A (1988), Scattering time and single-particle relaxation time in a disordered two-dimensional electron gas ", Phys Rev B 38, 10798 140 [29] Gerl C., Schmult S., Tranitz H.-P., Mitzkus C and Wegscheider W (2005), Carbon-doped symmetric GaAs/AlGaAs quantum wells with hole mobilities beyond 106 cm2/Vs", Appl Phys Lett Vol 86, 252105 [30] Gerl C., Schmult S., Wurstbauer U., Tranitz H.-P., Mitzkus and Wegscheider W (2006), Carbon-doped high-mobility hole gases on (001) and (110) GaAs", Physica E Vol 32, 258 C [31] G¡miz F., Rold an J B., Godoy A and Cartujo - Cassinello P (2003), Electron mobility in double gate silicon on insulator transistors: Symmetric-gate versus asymmetric-gate configuration", J Appl Phys Vol 94, 5732 [32] Goodnick S M., Ferry D K., Wilmsen C W., Liliental Z., Fathy D and Krivanek O L (1985), Surface roughness at the Si(100) SiO2 interface", Phys Rev B Vol 32, 8171 [33] Harris J J., Lee K J., Wang T., Sakai S., Bougrioua Z., Moer-man I., Thrush E J., Webb J B., Tang H., Martin T., Maude D K and Portal J-C (2001), Relationship between classical and quantum lifetimes in AlGaN/GaN heterostructures", Semicond Sci Technol Vol 16, 402 [34] Hsu and Walukiewicz (2002), Transport-to-quantum lifetime ratios in AlGaN/GaN heterostructures ,Appl Phys Lett 80, 2508 [35] Irisawa T., Myronov M., Parker E H C., Nakagawa K., Murata M., Koh S and Shiraki Y (2003), Hole density dependence of effective mass, mobility and transport time in strained Ge channel modulation-doped heterostructures , Appl Phys Lett 82, 1425 141 [36] Irisawa T., H Miura, Ueno T., and Shiraki Y (2001), Channel Width Dependence of Mobility in Ge Channel Modulation-Doped Structures , Jpn J Appl Phys 40, 2694 [37] Jonson M (1976), Electron correlations in inversion layers , J Phys C 9, 3055 [38] Kahan A., Chi M and Friedman L (1994), Infrared transitions in strained-layer GexSi1 x=Si , J Appl Phys 75, 0812 [39] Laikhtman B and Kiehl R A (1993), Theoretical hole mobility in a narrow Si/SiGe quantum well , Phys Rev B 47, 10515 [40] Leitz C W., Currie M T., Lee M L., Cheng Z.-Y., Antoniadis D A., and Fitzgerald E A (2001), Hole mobility enhancements and alloy scattering-limited mobility in tensile strained Si/SiGe sur-face channel metal oxide semiconductor field-effect transistors , J Appl Phys 92, 3745 [41] Luhman D R., Tsui D C., Pfeiffer L N and West K W (2007), Electronic transport studies of a systematic series of GaAs/AlGaAs quantum wells , Appl Phys Lett 91, 072104 [42] Lorenzini P., Bougrioua Z., Tiberj A., Tauk R., Azize M., Sakow-icz M., Karpierz K and Knap W (2005), Quantum and trans-port lifetimes of two-dimensional electrons gas in AlGaN/GaN het-erostructures , Appl Phys Lett 87, 232107 [43] Lee M L., Leitz C W., Cheng Z., Pitera A J., Langdo T., Currie M T., Taraschi G., Fitzgerald E A., and Antoniadis D A (2001), Strained Ge channel p-type metal oxide semiconductor fieldeffect transistors grown on Si1 xGex=Si virtual substrates , Appl Phys Lett 79, 3344 142 [44] Lander R J P., Kearney M J., Horrell A I., Parker E H C., Phillips P J and Whall T E (1997), On the low-temperature mobility of holes in gated oxide Si/SiGe heterostructures , Semicond Sci Technol 12, 1064 [45] Monroe D., Xie Y H., Fitzgerald E A., Silverman P J and Watson G P (1993), Comparison of Mobility-limiting Mechanisms in High-mobility Si1-x Gex heterostructures , J Vac Sci Technol B 11, 1731 [46] Maeda N., Saitoh T., Tsubaki K., Nishida T and Kobayashi N (2000), Enhanced effect of polarization on electron transport properties in AlGaN/GaN double-heterostructure field-effect tran-sistors , Appl Phys Lett 76(21), pp 3118-3120 [47] Morris R J H., Grasby T J., Hammond R., Myronov M., Mironov O A., Leadley D R., Whall T E., Parker E H C., Currie M T., Leitz C W andFitzgerald E A (2004), High conductance Ge p-channel heterostructures realized by hybrid epitaxial growth , Semicond Sci Technol 19, L106 [48] Matsumoto Y and Uemura Y (1974), Jpn J Appl Phys.Suppl 2, pp 367-370 [49] Manfra M J., Pfeiffer L N., West K W., Stormer H L., Baldwin K W., Hsu J W P., Lang D V., and Molnar R J (2000), High-mobility AlGaN/GaN heterostructures grown by molecularbeam epitaxy on GaN templates prepared by hydride vapor phase epitaxy , Appl Phys Lett 77, 2888 [50] Manfra M J., Pfeiffer L N., West K W., Picciotto R de, Baldwin.K W (2005), High mobility two-dimensional hole system in 143 GaAs/AlGaAs quantum wells grown on (100) GaAs substrates , Appl Phys Lett 86, 162106 [51] Manfra M J., Simon S H., Baldwin K W., Sergent A M., West K W., Molnar R J and Caissie J (2004), Quantum and trans-port lifetimes in a tunable low-density AlGaN/GaN twodimensional electron gas , Appl Phys Lett 85, 5278 [52] Myronov M., Sawano K., and Shiraki Y (2006), Enhancement of hole mobility and carrier density in Ge quantum well of SiGe het-erostructure via implementation of double-side modulation doping , Appl Phys Lett 88, 252115 [53] Myronov M., Irisawa T., Koh S., Mironov O A., Whall T E., Parker E H C and Shiraki Y (2005), Temperature dependence of transport properties of high mobility holes in Ge quantum wells , Appl Phys Lett 97, 083701 [54] Nag B R., Mukhopadhyay S and Das M (1999), Interface roughness scattering-limited electron mobility in AlAs/GaAs and Ga0:5In0:5P=GaAs wells , Appl Phys Lett 86, 459 [55] Noda T., Tanaka M., and Sakaki H (1990), Correlation length of interface roughness and its enhancement in molecular beam epi-taxy grown GaAs/AlAs quantum wells studied by mobility mea-surement , Appl Phys Lett 57, 1651 [56] Penner U., Rucker H., and Yassievich I N (1998), Theory of interface roughness scattering in quantum wells , Semicond Sci Technol 13, 709 [57] P J Price, Ann Phys (N Y.)(1981), 133, 217 ; Surf Sci 113, 199 (1982); 143, 145 (1984) 144 [58] D N Quang and N H Tung (2008), Band-bending effects on the electronic properties of square quantum wells , Phys Rev B 77, pp.125335-125341 [59] D N Quang, N H Tung, D T Hien and T T Hai (2008), Key scattering mechanisms for holes in strained SiGe/Ge/SiGe square quantum wells , J Applied Phys 104, 113711 [60] D N Quang, N H Tung, D T Hien, and H A Huy (2007), Theory of the channel-width dependence of the low-temperature hole mobility in Ge-rich narrow square SiSiGeSi quantum wells , Phys Rev B 75, 073305 [61] D N Quang, N H Tung, V N Tuoc, N V Minh, H A Huy, and D T Hien (2006), Quantum and transport lifetimes due to roughnessinduced scattering of a two-dimensional electron gas in wurtzite group-III-nitride heterostructures , Phys Rev B 74, 205312 [62] D N Quang, N H Tung, V N Tuoc, T V Minh, and P N Phong (2005), Roughness-induced piezoelectric charges in wurtzite group-III-nitride heterostructures , Phys Rev B 72, 115337 [63] D N Quang, V N Tuoc, T D Huan, and P N Phong (2004), Low-temperature mobility of holes in Si/SiGe p-channel heterostructures , Phys Rev B 70, 195336 [64] D N Quang, N H Tung, D T Hien, and H A Huy (2007), Theory of the channel-width dependence of the low-temperature hole mobility in Ge-rich narrow square Si=SiGe=Si quantum wells , Phys Rev B 75, 073305 145 [65] D N Quang, V N Tuoc, and T D Huan (2003), Roughnessinduced piezoelectric scattering in lattice-mismatched semiconduc-tor quantum wells , Phys Rev B 68, 195316 [66] D N Quang, V.N Tuoc, N H Tung, and T D Huan (2002), Random Piezoelectric Field in Real [001]-Oriented Strain-Relaxed Semiconductor Heterostructures , Phys Rev Lett 89, 077601 [67] D N Quang, V.N Tuoc, N H Tung, and T D Huan (2003), Strain fluctuations in a real [001]-oriented zinc-blende-structure surface quantum well , Phys Rev B 68, 153306 [68] Rossner B., von Kanel H., Chrastina D., Isella G and Batlogg B (2006), 2-D hole gas with two-subband occupation in a strained Ge channel: Scattering mechanisms , Thin Solid Films 508, pp 351-354 [69] Srolovitz D J (1989), On the stability of surfaces of stressed solids , Acta Metall 37, 621 [70] Schaffer F (1997), High-mobility Si and Ge structures , Sci Tech-nol 12, 1515 [71] Stern F and Howard W E (1967), Properties of semiconductor surface inversion layers in the electric quantum limit , Semicond Phys Rev 163, 816 [72] Szmulowicz F., Elhamri S., Haugan H J., Brown G J and Mitchel W C (2007), Demonstration of interface-scatteringlimited electron mobilities in InAs/GaSb superlattices , J Appl Phys 101, 04706 146 [73] Schirbir J E., Fritz I J and Dawson L R (1985), Light-hole conduction in InGaAs/GaAs strained-layer superlattices , Appl Phys.Lett 46, 187 [74] Sawano K., Satoh H., Kunishi Y., Nakagawa K and Shiraki Y (2007), Strain and hole-density dependence of hole mobility in strained-Ge modulation-doped structures , Semicond Sei Technol 22, S161 [75] Schrieffer J, R (1957), Mobility in inversion layers: Theory and ex-periment Semiconductor Surface Physics, University of Pennsyvania Press, Philadelphia [76] Tsujino S., Falub C V., Muller E., Scheinert M., Diehl L., Gennser U., Fromherz T., Borak A., Sigg H., Grutzmacher D.,Campidelli Y., Kermarrec O and Bensahel D (2004), Hall mo-bility of narrow Si0:2Ge0:8=Si quantum wells on Si0:5Ge0:5 relaxed buffer substrates , Appl Phys Lett 84, 2829 [77] Tsuchiya T and Ando T (1993), Mobility enhancement in quantum wells by electronic-state modulation , Phys Rev B 48, 4599 [78] Ullrich C A and Vignale G (2001), Theory of the Linewidth of Intersubband Plasmons in Quantum Wells , Phys Rev Lett 87, 037402 [79] Unuma T., Yoshita M., Noda T., Sakaki H and Akiyama H (2003), Intersubband absorption linewidth in GaAs quantum wells due to scattering by interface roughness, phonons, alloy disorder, and impurities , J Appl Phys 93, 1586 [80] Van de Walle C G (1989), Band lineups and deformation poten-tials in the model-solid theory’, Phys Rev B 39, 1871 147 [81] Venkataraman V., Liu C W and Sturm J C (1993), Alloy scattering limited transport of two-dimensional carriers in strained Si1xGex quantum wells , Appl Phys Lett 63, 2795 [82] Whall T E and Parker E H C (1998), SiGe heterostructures for FET applications , J Phys D 31, 1397 [83] Xie Y H., Monroe D., Fitzgerald E A., Silverman P J., Thiel F A and Watson G P (1993), Very high mobility two-dimensional hole gas in Si=GexSi1x=Ge structures grown by molecular beam epitaxy , Appl Phys Lett 63, 2263 [84] Yang B., Cheng Y., Wang Z., Liang J., Liao.Q., Lin L., Zhu Z., Xu B and Li W (1994), Interface roughness scattering in GaAs=AlGaAs modulation-doped heterostructures , Appl Phys Lett 65, 3329 [85] Zanato D., Gokden S., Balkan., Ridley N and Schaff W J (2004), The effect of interface-roughness and dislocation scattering on low temperature mobility of 2D electron gas in GaN/AlGaN , Semicond Sci Technol 19, 427 148 PHÖ LÖC Trong phƒn phư lưc chóng tỉi ÷a mºt sŁ h m phö döng lu“n ¡n (n cos n + sin n ) ; vỵi n = 0; 1; 2; ::: n( )= ! n( ) = ( n(x) vỵi n = 0; 1; 2; ::: n(x) = = ữổc sò (4.13) (4.14) (4.10) (4.15) (4.16) (4.11) (4.12) (4.17) 149 ... thíi gian sŁng v k‚t lun vã hai i lữổng trản nhiãu trữớng hổp l ỗng nhĐt Thới gian sng chuyn v thới gian sng lữổng tò Thới gian sng chuyn v lữổng tò l hai i lữổng quan trồng i mt hằ lữổng tò Trong. .. iằn tò hai chiãu  cho thĐy sỹ khĂc biằt rê rằt gia hai lo⁄i thíi gian sŁng hay cỈn gåi l thíi gian hỗi phửc n y [14] nh nghắa Thới gian sng v“n chuy”n Thíi gian sŁng v“n chuy”n t (hay thíi gian. .. gian sŁng v“n chuy”n ÷ỉc rót o linh ng Hall vợi t trữớng yu Thới gian sng khĂc l thới gian sng lữổng tò q l thới gian trung bnh m ht tỗn ti trản mt trng thĂi lữổng tò tỗn ti cĂc tĂn x Thới gian