我們利用表面光電壓光譜(SPS)、光激螢光激發光譜(PL)及螢光激發光譜(PLE)三種量測方式來探討由固態源分子束磊晶(SSMBE)所組成的砷化銦/砷化鎵量子點結構中有無覆蓋砷化銦鎵層的光學特性。利用此三種量測方式，我們可以清楚的觀察到砷化銦量子點的基態和激發態的訊號、濕層、砷化銦鎵層和砷化鎵層的訊號。至於有關砷化銦鎵層的訊號可由砷化銦濕層及砷化銦鎵所組成量子井系統中可得知，並利用模擬的結果加以證實。此外，亦可利用濕層訊號有無產生能帶分裂來證明砷化銦鎵層有減少應力產生的作用。而量子點訊號基態及激發態的紅移則為應力分佈的改變及量子點的尺寸變大所造成。最後則利用Varshni 經驗式吻合分析各躍遷訊號對溫度的變化求出Varshni parameters；而由量子點訊號之較低的α值證實量子點躍遷能階對溫度的變化較為穩定的特性。此外從本文中我們可以得知SPS的量測技術可與PLE互補且為非破壞性的量測方式，是一種可用來檢測量子點結構樣品的利器。

Surface photovoltage spectroscopy (SPS), photoluminescence (PL) and photoluminescence excitation (PLE) techniques have been used to characterize the self-assembled InAs/GaAs quantum dots (QDs) structures with and without InGaAs overgrown layers grown by solid source molecular beam epitaxy (SSMBE). Signals from barrier, wetting layer (WL), overgrown layer, ground state and excited states of the QDs have been observed and identified. The effects of the InGaAs overgrowth layer have been studied in detail. The information on the decomposition of the InGaAs layer has been obtained from the electronic transition properties of the quantum well (QW) formed by the InAs WL and the InGaAs layer.
The effects of the InGaAs overgrowth layer have been studied in detail. The observed reduction in the energy splitting in the energy splitting of the heave- and light-hole in the wetting layer indicate a partial strain relaxation due to the InGaAs overgrown layer. The red shifts of the ground state and excited states transition energies of QDs have been attributed to the altered strain distribution and increase of QD size. The optical properties of the InAs QDs, WL, QW, and GaAs were studied with the fitting parameters using Varshni’s equation. The SPS has been shown to be a complementary technique to PL and PLE, and can be used for nondestructive characterization of self-assembled QDs structures.

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