Molecular Beam Epitaxy (MBE) is a method for making high purity, tensile-strained GaAs quantum dots (QDs) embedded in solid-state semiconductors. QDs, excited by electricity or lasers, emit photons characteristic of the QDs size and composition, which may be used in tunable optoelectronic devices such as LEDs, lasers and solar cells. Understanding the light emission properties of these QDs is essential for these applications, as well as for continued QD research. Photoluminescence (PL) is a laser-excitation technique used to determine these properties. Occasionally, the PL signals from our samples are too low in intensity to be accurately detected. We will investigate whether the addition of gold coatings on the back of QD samples improves PL emission by reflecting additional photons into the detector. To apply these reflective coatings, we first prepare the samples using a chemical wet etch process and then deposit thin gold films via physical vapor deposition. We will analyze the difference in PL intensity between coated and noncoated samples and gauge the influence of gold deposition thickness
