Enhancement of Photoluminescence of Semiconductor Quantum Wells Using Two-Dimensional Material Quantum Dots

• Main Authors: Chia-Cheng Chiang Hsieh, 江謝家成
• Other Authors: J.L. Shen
• Format: Others
• Language: zh-TW
• Published: 2019
• Online Access: http://ndltd.ncl.edu.tw/handle/a74x2w

碩士 === 中原大學 === 物理研究所 === 107 === In this thesis, tungsten disulfide quantum dots (WS2 QDs) and graphene quantum dots (GQDs) each doped with asparagine were successfully fabricated via microwave-assisted synthesis and laser ablation, respectively. The successful synthesis of both QDs were demonstrated by transmission electron microscopy (TEM), photoluminescence (PL) spectra and ultraviolet-visible (UV-Vis) absorption spectra. To confirm the successful doping of aspargine in the QDs, Xray photoelectron spectroscopy (XPS) was used. The Raman scattering properties of Si-δ-doped indium gallium arsenide (InGaAs) and aluminum gallium arsenide (AlGaAs) quantum wells with high sensitivity two-dimensional electron gas Hall magnetic sensor elements are discussed. It is found that the Raman asymmetry depends on Si. With higher amount of delta doping the more asymmetric the Raman spectra shows. We suggest that doping defects on the surface of the quantum well demonstrates pronounced asymmetry. Here, the as-synthesized WS2 QDs and GQDs were used as separate dopants to both quantum wells via drop-casting method. It is found that the photo-excited fluorescence of both quantum wells are enhanced. Recombination kinetics analysis showed that carrier transfer is responsible for the enhancement of PL intensity via QDs doping.