具有表面銀奈米顆粒薄p-型層綠光發光二極體的表面電漿子耦合效應

Abstract

我們首先展示具有p-型層厚度僅38奈米的高效率發光二極體，藉由預先通入鎂的方式，我們可以增加p-型氮化鋁鎵電子阻擋層內的鎂摻雜濃度及電洞農度，由此發光二極體電洞的注入效率能夠大幅度提升。基於這項技術，在p-型層極薄的情況下仍能維持發光二極體的高效率表現。然後，我們比較不同p-型層厚度之發光二極體的表面電漿子耦合效應，包括內部量子效率的增加、發光強度的增強、高效率滑落效應的降低以及調製頻寬的提升。隨著發光二極體的p-型層變薄，這些有益的效應會更加強烈。然而，這些效應隨著p-型層厚度的變化幅度不盡相同。在元件半徑為10微米的條件下，我們於c-平面氮化鎵系之發光二極體實現605.6 MHz的高調製頻寬。

The high performance of a light-emitting diode (LED) with the total p-type thickness as small as 38 nm is first demonstrated. By increasing the Mg doping concentration in the p-AlGaN electron blocking layer through an Mg pre-flow process, the hole injection efficiency can be significantly enhanced. Based on this technique, the high LED performance can be maintained with a thin p-type layer. Then, the surface plasmon coupling effects, including the enhancement of internal quantum efficiency, increase of output intensity, reduction of efficiency droop, and increase of modulation bandwidth, among the thin p-type LED samples of different p-type thicknesses are compared. These advantageous effects are stronger as the p-type layer becomes thinner. However, the dependencies of these effects on p-type layer thickness vary. With a circular mesa size of 10 μm in radius, we achieve the high modulation bandwidth of 605.6 MHz among c-plane GaN-based LEDs.