In-situ measurements of the irradiation effects in semiconductors under high energy ion irradiation

通过测量辐照下的发光光谱，分析了高能离子在各种半导体中引起的高密度激发效应和局域高温态。用OMA测量时间积分发光光谱。时间分辨光谱测量与时间相关。单光子计数系统，通过多通道板探测离子穿过碳箔时发射的二次电子来确定离子到达时间，首次通过测量有机-无机层状钙钛矿材料的发光光谱，成功地观测到了离子轨迹上的瞬态局部高温态沿着，已知其形成天然的多量子阱结构并由于自由激子而呈现快速发光。此外，从观察到的局域温度与激发态密度的关系中，发现了局域熔化现象。其次，我们分析了激发态的空间行为 ...更多信息 艾德载流子的时间分辨发光光谱。通过分析电子-空穴等离子体产生的快铝发光带的光谱形状，估算了辐射复合时受激载流子的密度和平均能量。所得到的结果可以定量地解释内的扩散模型，其中激发载流子的极性光学散射被考虑。此外，我们测量了MgO的单晶，其中的电子晶格耦合比在半导体中稍强的发光光谱。随着激发密度的增加，由于自由激子的发光带的强度降低，并最终消失。相比之下，自由激子带的低能侧出现了另一个发光带。与传统半导体的情况类似，我们将自由激子带的消失和新带的出现分别归因于库仑相互作用的屏蔽和类似于电子空穴等离子体的集体激发态中的辐射复合。少

We analyzed the high-density excitation effects and local high temperature state induced by energetic ions in various semiconductors by measuring the luminescence spectra under irradiation. Time-integrated luminescence spectra were measured with an OMA. Time-resolved spectra were measured with a time-correlated. single photon counting system, which determined the arrival time of ions by detecting with multichannel plates the secondary electrons emitted when the ions transmit a carbon foil.At first, we have succeeded in observing the transient local high-temperature state along an ion trajectory by measuring the luminescence spectra of organic-inorganic layered perovskite materials, which is known to form a natural multiple quantum well structure and exhibit fast luminescence due to free excitons. Furthermore, from the relation between the observed local temperature and the excitation density, it was found that local melting occurs.Secondly, we analyzed the spatial behavior of the excit … More ed carriers from the time-resolved luminescence spectra of CdS. By analyzing the spectral shape of a fast aluminescence band due to electron-hole plasma, we estimated the density and the average energy of the excited carriers when radiative recombination occurs. The obtained results can be quantitatively explained within the diffusion model where polar optical scattering of the excited carriers is taken into account.In addition, we measured the luminescence spectra of a single crystal of MgO, in which the electron lattice coupling is slightly stronger than in semiconductors. As the excitation density increased, a luminescence band due to free excitons reduced its intensity, and finally disappeared. In contrast, another luminescence band appeared at the low-energy side of the free exciton band. Similarly to the case of conventional semiconductors, we attributed the disappearance of the free exciton band and the appearance of the new band to the screening of the Coulomb interaction and the radiative recombination in the collective excited states analogous to the electron hole plasma, respectively. Less