Low Temperature Growth and Conductivity Control of High Quality ZnS Layrs Grown by Using High TemperatureE Molecular Beams

高温E分子束生长高质量ZnS层的低温生长和电导率控制

• 批准号: 07650026
• 负责人: OHISHI Masakazu
• 金额: $ 1.34万
• 依托单位: Okayama University of Science
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1995
• 资助国家: 日本
• 起止时间: 1995 至 1996
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-07650026/
• 关键词: Zincsulfide; Molecular Beam Epitaxy; Crystal Growth; Doping; Growth rate; Surface; RHEED; Luminescence; MBE成長; 分子線ユピタキシ-; 低温成長; 硫化亜鉛薄膜

In this study, , ZnS/GaAs and ZnSe/GaAs epitaxial layrs were grown on GaAs (001) and misoriented GaAs (001) substrates by a molecular beam epitaxy (MBE), and their growth process were studied by means of a reflection high energy electron diffracti on (RHEED) , and the growth rate of epitaxial layr and the optical property were investigated. The molecular beams used in present experiment are post-heated molecular beams exhausted from the effusion cell equipped with extra heater at the outlet of conventional K cell.As P-type acceptor dopant, Li beam is supplied onto the growing surface form conventional K cell using elemental Li. We found that the curved streaks appear in the RHEED pattern during and after MBE growth. The origin of curved streaks are attributed to the one-dimensional Li-related lattice, ie., Li atoms are selectively captured by Se atoms at B-step edge of surface terrace. Furthermore, if Li atoms are suppled on GaAs (001) -just surface, the layr growth rate decreases and … More if Li beam flux exceeds a certain amount, no epitaxial growth takes places. This means that the growth of Li highly doped layr with sufficient thickness is difficult. The reason of growth rate reduction is attributed to the B-type teminated with Li atoms obtacle the layrer growth from these step edges. However, we found that the growth rate reduction does not occur, if the misoriented GaAs substrates (15ﾟoff) are used.In Li-doped ZnS and ZnSe layrs, the emission from Li-acceptor bound exciton (I_1) , FA and DAP emissions dominate the PL sectrum and other emissions are very weak, which denotes the epitaxial layrs are high Purity. The dominace of FA emission means that the concentration of donor-like impurities such as interstitial Li is extremely low. Thus, we can say that the MBE growth using post-heated molecular beams are an effective method to grow Li-doped epitaxial layrs.We also found puzzuling behvior of Iv emiison obserev in the PL spectra of undoped-ZnSe/GaAs, i.e., the emission intensity increases during PL measurement. We concluded that the emission center for Iv emission is formed by Se vacancy and photo-excited carriers. Less

本研究采用分子束外延(MBE)技术在GaAs(001)和定向GaAs(001)衬底上生长了ZnS/GaAs和ZnSe/GaAs外延层,并通过反射高能电子衍射(RHEED)研究了它们的生长过程,并考察了外延层的生长速率和光学性能。本实验中使用的分子束是从传统K电池出口处配备有额外加热器的喷射池中排出的后加热分子束。作为P型受体掺杂剂，Li束被提供到使用元素Li的传统K电池的生长表面上。我们发现在 MBE 生长期间和之后，RHEED 图案中出现弯曲条纹。弯曲条纹的起源归因于一维Li相关晶格，即Li原子在表面台阶的B阶边缘处被Se原子选择性捕获。此外，如果Li原子仅供给GaAs（001）表面，则层生长速率会降低，并且如果Li束通量超过一定量，则不会发生外延生长。这意味着生长足够厚度的Li高掺杂层是困难的。生长速率降低的原因归因于以Li原子终止的B型阻碍了这些台阶边缘的层生长。然而，我们发现，如果使用定向错误的GaAs衬底（15ﾟoff），生长速率不会发生降低。在Li掺杂的ZnS和ZnSe层中，来自Li受体束缚激子（I_1）的发射、FA和DAP发射在PL光谱中占主导地位，其他发射非常弱，这表明外延层的纯度很高。 FA 发射的主导意味着诸如间隙 Li 等供体类杂质的浓度极低。因此，我们可以说，使用后加热分子束的MBE生长是生长Li掺杂外延层的有效方法。我们还在未掺杂的ZnSe/GaAs的PL光谱中发现了令人费解的Iv发射观察行为，即PL测量期间发射强度增加。我们得出结论，Iv 发射的发射中心是由 Se 空位和光激发载流子形成的。较少的

项目成果

M. Yoneta: "Photo‐Active Defect‐Related Luminescence Line Observed ZnSe/GaAs Grown by Molecular Beam Epitaxy" J. Crystal Growth. 159. 148-151 (1996)

M. Yoneta：“通过分子束外延生长观察到的光活性缺陷相关发光线”J. Crystal Growth 159. 148-151 (1996)

H.Saito, M.Yoneta, M.Ohishi, H.Kobashi, C.Hatano and K.Kitani: "Acceptor-doping in ZnS/GaAs grown by means of the post-heated molecular beam epitaxy" Matrials Science Forum. 182-184. 69-72 (1995)

H.Saito、M.Yoneta、M.Ohishi、H.Kobashi、C.Hatano 和 K.Kitani：“通过后加热分子束外延生长的 ZnS/GaAs 中的受主掺杂”材料科学论坛。

M.Yoneta: "Photo-active defect-related luminescence line observed in ZnSe/GaAs Grown by Molecular Beam Epitaxy" J.Crystal Growth. 159. 148-151 (1996)

M.Yoneta：“在分子束外延生长的 ZnSe/GaAs 中观察到的光活性缺陷相关发光线”J.Crystal Growth。

M.Yoneta, H.Saito, M.Ohishi, K,Kitami, H.Kobashi and C.Hatano: "Li-acceptor doping in ZnS/GaAs by post-heated molecular beam epitaxy" J.Crystal Growth. 150. 817-822 (1995)

M.Yoneta、H.Saito、M.Ohishi、K、Kitami、H.Kobashi 和 C.Hatano：“通过后加热分子束外延在 ZnS/GaAs 中进行锂受体掺杂”J.Crystal Growth。

M. Yoneta: "Photo-Active Defect-Related Luminescence Line Observed in ZnSe/GaAs Grown by Molecular Beam Epitaxy" J. Crystal Growth. (印刷中). (1996)

M. Yoneta：“在分子束外延生长的 ZnSe/GaAs 中观察到的光活性缺陷相关发光线”J. Crystal Growth（出版中）。