MBE生长轻掺Si高迁移率GaAs材料的杂质补偿特性研究

报道了用MBE生长轻掺Si高迁移率GaAs材料的杂质补偿特性实验研究。已得到77K温度下迁移率为16.2×10~4cm~2/(V·s)的GaAs材料。样品的Hall测量结果表明:在较低的杂质浓度范围(1×10~(13)cm~(-3)＜n＜1×10~(15)cm~(-3))内,在大体相同的生长温度(590℃左右)下,选择适当的生长速率Gr会增强对浅受主杂质的抑制作用,同时也会一致Si的自补偿效应,减小杂质的补偿度N_a/N_d之值,从而提高MBE外延GaAs材料的迁移率

MBE生长面发射激光器的原位厚度监测

在MBE生长"DBR型结构性材料"的过程中,由于生长中的多层结构干涉效应,使高温黑体辐射谱呈现振荡现象,利用此现象辅以计算机数据拟合,可以实现MBE生长中层次、组分和厚度的实时监控,对MBE系统生长垂直腔型结构材料的实时质量监控有重要意义.利用红外高温仪对VCSEL器件生长全过程(包括谐振腔)及多种组分DBR的表观衬底热辐射振荡进行监测,采用准黑体模型,结合扫描电镜、光反射谱等结果进行了分析,理论与实验得到了较好的吻合

Effects of Rapid Thermal Annealing on OpticalProperties of GaInNAs/ GaAs Single Quantum Well Grown by Plasma- Assisted Molecular Beam Epitaxy

The effects of Rapid Thermal Annealing (RTA) were experimentally investigated. Ion removal magnets were applied to reduce the ion damage during the growth process and the optical properties of GaInNAs/GaAs SQW were remarkably improved. RTA was carried out at 650 ??C and its effect was studied by comparing the room temperature PhotoLuminescence (PL) spectra for the non ion-removed (grown without magnets) sample with the ones for the ion-removed (grown with magnets) sample. The more significant improvement of PL characteristics for non ion-removed GaInNAs/GaAs SQW after annealing (compared with those for ion-removed )indicates that the nonradiative centers removed by RTA at 650??C are mainly originated from ion damage. After annealing the PL blue shift for non ion removed GaInNAs/GaAs SQW is much larger than those for InGaAs/GaAs and ion-removed GaInNAs/GaAs SQW. It is found that the larger PL blue shift of GaInNAs/GaAs SQW is due to the defect-assisted In-Ga interdiffusion rather than defect-assisted N-As interdiffusion.国家自然科学基金,国家攀登计划EI中文核心期刊要目总览(PKU)中国科学引文数据库(CSCD)109742

分子束外延生长高应变单量子阱激光器（英文）

采用分子束外延方法研究了高应变InGaAs/GaAs量子阱的生长技术。将InGaAs/GaAs量子阱的室温光致发光波长拓展至1160nm，其光致发光峰半峰宽只有22meV。研制出1120nm室温连续工作的InGaAs/GaAs单量子阱激光器。对于100μm条宽和800μm腔长的激光器，最大线性输出功率达到200mW，斜率效率达到0.84mW/mA，最低阈值电流密度为450A/cm~2，特征温度达到90K

MBE InGaAs/GaAs外延层晶胞弛豫直接测量的X射线双晶衍射方法

采用了以解理面为衍射基面,直接测量水平弛豫的方法测量了In_xGa_(1-x)As(衬底为GaAs,X-0.1)外延层的应变及其弛豫状态。在以解理面为衍射基面的衍射曲线上清楚地观测到了衬底峰与外延峰的分裂。表明当InGaAs层厚度较厚(-2μm)时，InGaAs外延层与衬底GaAs已处于非共格生长状态，同时发现大失配的InGaAs晶胞并没有完全弛豫恢复到自由状态。其平行于表面法线的晶格参数略大于垂直方向上的晶格参数(△α/α-10~(-3))。并且晶胞在弛豫过程中产生了切向应变。在考虑了切向应变的基础上准确地确定出了InGaAs层的In组分x

离子损伤对等离子体辅助分子束外延生长的 Ga NAs/ Ga As和Ga In NAs/ Ga As量子阱的影响（英文）

研究了离子损伤对等离子体辅助分子束外延生长的GaNAs/GaAs和GaInNAs/GaAs量子阱的影响。研究表明离子损伤是影响GaNAs和GaInNAs量子阱质量的关键因素。去离子磁场能有效地去除了等离子体活化产生的氮离子。对于使用去离子磁场生长的GaNAs和GaInNAs量子阱样品，X射线衍射测量和PL谱测量都表明样品的质量被显著地提高。GaInAs量子阱的PL强度已经提高到可以和同样条件下生长的GaInAs量子阱相比较，研究也表明使用的磁场强度越强，样品的光学质量提高越明显

GaN_xAs_1-x/GaAs单量子阱发光性质及带阶研究

用光熒光譜 (PL )研究了 Ga Nx As1 - x/ Ga As單量子阱 (SQW)的光躍遷性質和帶階 .通過研究積分熒光強度與激發強度的關系及光譜峰值位置與溫度的關系 ,發現 Ga Nx As1 - x/ Ga As單量子阱中的發光是本征帶 -帶躍遷 ,并且低溫發光是局域激子發光 .通過自洽計算發現它的導帶帶階 (ΔEc)與氮含量的關系不是純粹的線性關系 ,其平均變化速率 (0 .110 e V / N% )比文獻中報道的要慢得多 (0 .15 6～ 0 .175 e V / N% ) ,此外發現 Qc(=ΔEc/Δ Eg)隨氮含量的變化很小 ,可以用 Qc≈ x0 .2 5 來表示 .還研究了 Ga Nx As1 - x/ Ga As單量子阱中氮含量的變化對能帶彎曲參數 (b)的影響. The optical pro perties and the band lineup in GaN As/GaAs sing le qua ntum w ells ( SQWs) g row n by mo lecula r beam epitax y ( MBE) using photo luminescence ( PL) tech nique we re investiga ted. It wa s fo und that the low -tem per ature PL is dominated by the intrinsic localized ex cito n emissio n. By fitting the ex perimental dataw ith a simple calculatio n, ba nd o ffset of the GaN0. 015 As0. 985 /GaAs he tero structure wa s estima ted. Mor eov er, ΔEc , the disco ntinuity of the co nduc tion band w as found to be a nonlinea r functio n o f the nitr og en compo sitio n ( x ) and the av erag e v ariation of ΔEc is abo ut 0. 110eV per % N, such smalle r tha n that reported o n the literatur e ( 0. 156～ 0. 175 eV /N% ). In additio n, Qc has little chang e whtn N compositio n incr ea res, with a n ex perimential relation of Qc≈x 0. 25 . The ba nd bowing co efficient ( b) w as also studied in this pa per. Th e measured ba nd bowing co efficient sh ow s a str ong function o f x , giv ing an ex perimenta l suppo rt to the theo retic ca lcula tio n o f Wei Su-Huai and Zunger Alex ( 1996)