Materials for new semiconductor lasers; atomically-controlled, growth of rare-earth-doped III-V semiconductors with high quality

稀土（RE）掺杂的半导体作为一类有前途的新型材料受到了极大的关注，其通过电注入从RE 4f壳层发光，其中电子-空穴对的能量被转移到RE壳层。稀土离子的4f壳层内跃迁产生尖锐的发射线，其波长在很大程度上与基质材料和温度无关。这种稳定性是因为填充的5s和5 p电子外层。屏幕内的4f电子壳层与主机的相互作用过渡。4f内壳层从第一激发态（4^I_<13/2>）到基态由于Er^<3+>离子在1.5 μm附近的波长与用于光通信的石英光纤的最小损耗区域相匹配，因此Er^<3+>离子在1.5 μm附近的（4 ^I_<15/2>）具有特别的兴趣。我们研究了原子控制生长用于新型发光器件的高质量掺铒GaAs。结果obt ...更多信息 通过优化反应器结构和生长温度，成功地实现了不同V族元素组成的异质界面组分突变。2）通过Er和O共掺杂GaAs，选择性地形成Er-20组态，使发光强度提高了两个数量级。在室温下，通过注入电流，在GaInP/GaAs：Er，O/GaAs双异质结中观察到了Er相关的发光。EL光谱以Er-20线为主，表明Er-20中心成功形成，并且通过电流注入优先激发该中心。4）EL强度的电流密度依赖性揭示了电流注入对Er离子的极大激发截面，约为10^<-15>cm 2。通过时间分辨测量证实了大的激发截面。的EL强度。它比掺Er的Si LED（6x 10 ^cm ^2）大两个数量级<-17>。少

Rare-earth (RE) doped semiconductors have gained significant attention as a promising new class of materials that emit light from the RE 4f shell by means of electrical injection, in which the energy of electron-hole pairs is transferred to the RE shell. The intra-4f shell transitions of RE ions give rise to sharp emission lines whose wavelengths are largely independent of both the host materials and temperature. This stability occurs because the filled outer 5s and 5p electron shells. screen transitions within the inner 4f electron shell from the interaction with the host. The intra-4f shell transitions from the first excited state (4^I_<13/2>) to the ground state (4^I_<15/2>) of Er^<3+> ions at around 1.5 μm is of special interest because the wavelength matches the minimum loss region of silica fibers used in optical communications.In this research project, we investigated atomically-controlled growth of Er-doped GaAs with high quality for new-type light-emitting devices. Results obt … More ained experimentally are summarized as follows1)By optimizing reactor structure and growth temperature, the abrupt change in composition at the heterointerface consisting of different group-V elements was successfully obtained.2)Er-20 configuration was selectively formed by codoping Er and O to GaAs, resulting in the increase in PL intensity by two orders in magnitude: The amount of O in growth ambient played an important role for the intensity increase.3)Er-related luminescence was observed in GaInP/GaAs : Er, O/GaAs doubleheterostructures by injecting, current at room temperature. The EL spectrum was dominated by Er-20 lines, suggesting a successful formation of the Er-20 center and a preferential excitation of the center by current injection.4)The current density dependence of the EL intensity revealed an extremely large excitation cross section of Er ions by current injection, approximately 10^<-15> cm^2. The large excitation cross section was confirmed by time-resolved measurements. of the EL intensity. It is by two orders in magnitude larger than that of Er-doped Si LEDs (6x10^<-17> cm^2). Less