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在半导体ZnS衬底上依次蒸发淀积半绝缘ZnS层和Au,Pt或Ag电极制成了MIS器件。对在445到460nm范围呈现正向偏压蓝色电致发光的二极管进行了广泛地研究。具有最佳量子效率的二极管(Ⅰ层厚度约为350至500(?))其光电势垒高度也较大(≈2.4ev),并指出半导体在界面处严重反转。少数载流子的补充来自从金属经由半绝缘层价带的热空穴迁移。当能量相当于势垒高度的热电子进入金属时,在低效MS二极管的发射为等离子体发光。这证实了如下论点:当高能电子去激励时,在金属中将产生象热空穴那样的少数载流子。在大约1.85V的阀值电压以上,观测到形式为B—J~#的亮度—电流密度变化规律(n变化于2.0～1.5之间),其变化范围超过六个数量级。在最大驱动电流下对效率的限制似乎是缺乏足够的载流子。本器件最大的适用电流密度由于有200至500Ω的高串连电阻,一般限制在10到20mA mm~(-2)。
A MIS device was fabricated by sequentially vapor depositing a semi-insulating ZnS layer and Au, Pt or Ag electrodes on a semiconductor ZnS substrate. Diodes that exhibit forward-biased blue electroluminescence in the 445 to 460 nm range have been studied extensively. The diode with the best quantum efficiency (I layer has a thickness of about 350 to 500 (?)) Also has a large photovoltaic barrier height (? 2.4 eV) and indicates that the semiconductor is seriously reversed at the interface. Minority carrier replenishment results from hot hole transport from the metal via the valence band of the semi-insulating layer. When hot electrons with energies equivalent to the barrier heights enter the metal, the emission at the inefficient MS diode is plasma glow. This confirms the argument that when energetic electrons de-energize, minority carriers like hot holes will be created in the metal. Above the threshold voltage of about 1.85V, the brightness-current density variation in the form of B-J ~ # was observed (n varies between 2.0 and 1.5) over a six-fold range. The limitation of efficiency at maximum drive current appears to be the lack of sufficient carriers. The maximum applicable current density of this device is generally limited to 10 to 20mA mm ~ (-2) due to the high series resistance of 200 to 500Ω.