Ⅲ-Ⅴ族氮化物半導體的研究與應用已經很廣泛，由於Ⅲ-Ⅴ族氮化物屬於直接能隙、寬能帶的材料，在550 nm以下的波長範圍，有很高的發光效率，而表面電漿共振效應可進一步提升氮化物半導體的發光效率。表面電漿共振是存在於金屬與介電質的介面處，當光波的頻率與金屬表面自由電子的頻率一致時，金屬表面的電子會發生集體震盪，大幅增加氮化物量子井的發光效率。 本研究採用氮化銦鎵量子井作為介電質，分別搭配金薄膜和銀薄膜，以形成表面電漿效應。我們分析金、銀薄膜對量子井發光頻譜的影響，發現10 nm厚的銀會使量子井發出很強的紅光(~ 650 nm)，金薄膜則無此現象。我們認為此強烈紅光來自於銀與量子井所匹配而成的表面電漿效應。量子井所發出的紅光強度，會因銀表面折射率的改變，而產生變化。此現象在生醫感測上有一定的應用價值，可用來感測生物分子結合所產生的折射率變化。 ;III-V nitride semiconductors have been applied on various types of optoelectronic devices.. Owing to its direct and wide-spanned energy gap, the compound exhibits exceptionally high radiative recombination rate at the wavelengths below 550 nm. If integrated with a surface plasma resonance (SPR) structure, the quantum wells (QWs) made of nitride compounds can produce much intensified emission spectra. The SPR phenomenon exists at the interface between metal and dielectric. When the frequency of an incident light matches that of the free electrons on metal surface, the radiative recombination efficiency of the QWs can be boosted. In this research, InGaN QWs are used as the dielectric material to induce the SPR effect with the metal film made of Au or Ag. It is found that the QWs capped with a 10-nm Ag exhibit strong emission at the wavelengths around 650 nm, which is not observed the QWs capped with Au. The result was due to the SPR effect induced by the Ag film. The intensity of the strong red emission is found to be changed upon the variation of refractive index on the Ag surface. The index-dependency of red emission is a potential tool for SPR biosensors, as the biomolecular interactions can be detected by the change of emission intensity.
