TitleMOCVD growth of MGxZN1-xO films and nanostructures for photovoltaics
NameDuan, Ziqing (author), Lu, Yicheng (chair), Jiang, Wei (internal member), Jeon, Jaeseok (internal member), Lai, Warren (internal member), Cosandey, Frederic (outside member), Rutgers University, Graduate School - New Brunswick,
SubjectElectrical and Computer Engineering,
Metal organic chemical vapor deposition,
Photovoltaic power generation
DescriptionMGxZN1-xO, which is formed by alloying ZnO with MgO, has been developed as a promising window layer in chalcopyrite thin film solar cells and hybrid polymer solar cells for enhanced open-circuit voltage and solar conversion efficiency because of its bandgap tunability. The surface morphology of MgxZn1-xO layers in those photovoltaic applications plays important roles on the performances of solar cells. Two-dimensional (2-D) dense and smooth film is preferred in the inorganic p-n junction solar cells while one-dimensional (1-D) nanostructures are favorable for the hybrid polymer solar cells. In this dissertation, metal-organic chemical vapor deposition (MOCVD) is used to grow both of MgxZn1-xO polycrystalline 2-D films and single crystalline 1-D nanostructures for solar cells. A low-temperature (~250oC) ZnO buffer layer, followed by the high-temperature (~500oC) growth of MgxZn1-xO, is found to be beneficial for the formation of a 2-D dense and smooth film. On the other hand, a high-temperature (~520oC) ZnO buffer layer followed by a high temperature (530oC-560oC) growth of MgxZn1-xO is needed to grow the 1-D MgxZn1-xO (0≤x≤0.15) nanostructures on Si. For the first time, 1-D MgxZn1-xO nanostructures (0≤x≤0.1) are sequentially grown on a Ga-doped ZnO (GZO) 2-D film to form the 3-D photoelectrode, which is used to fabricate the P3HT-MgxZn1-xO hybride solar cells. The preliminary testing results of solar cells show that MgxZn1-xO is promising to be used in hybrid polymer solar cells for the enhancement of open circuit voltage (VOC). MgxZn1-xO (0≤x≤0.1) polycrystalline films are used in Cu2O-MgxZn1-xO heterojunction solar cells. The current density-voltage (J-V) measurements of solar cells under illumination show that VOC, shunt resistance Rsh and the solar conversion efficiency η are improved with increasing of Mg% until 10%. A relatively high solar conversion efficiency, ηAM1.5 = 0.71 % with a short circuit current JSC = 3.0 mA/cm2 and VOC = 575 mV, is obtained on the Mg0.1Zn0.9O sample. The band alignment between Cu2O and MgxZn1-xO is analyzed by using X-ray photoelectron spectroscopy (XPS) measurements.
NoteIncludes bibliographical references
Noteby Ziqing Duan
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.