Deep level donor＇s ionization behavior of passive film formed on the surface of stainless steel was investigated by Mott-Schottky plots. It is indicated that transformation process of deep level donors＇ ionization b...Deep level donor＇s ionization behavior of passive film formed on the surface of stainless steel was investigated by Mott-Schottky plots. It is indicated that transformation process of deep level donors＇ ionization behavior of passive film on surface of stainless steel can be divided into 4 stages with rising immersion time. At the initial immersion stage （10 min）, Fe（II） located in the octahedral sites of the unit cell is not ionized and the deep level does not appear in Mott-Schottky plots. At the second stage （9-38 h）, Fe（II） located in the octahedral sites starts to be ionized, which results in deep level donors＇ generation and density of deep level donors almost is constant with augmenting immersion time but the thickness of space charge layer is more and more thicker with rising immersion time. At the third stage （48 h-12 d）, density of deep level donors rises with increasing immersion time and the thickness of passive films space charge layer decreases. At last stage （above 23 d）, both the space charge layer＇s thickness and density of deep level donors are no longer changed with increasing immersion time. In the overall immersion stage, the shallow level donors＇ density is invariable all the time. The mechanism of deep level donor＇s ionization can be the generation of metal vacancies, which results in crystal lattice＇s aberration and the aberration energy urges the ionization of Fe（ II ） in octahedral sites.展开更多
A novel photovoltaic phenomenon of internal photoemission was found in a low cost manganite La0.62Ca0.29K0.09MnO3 （LCKMO）/zinc oxide （ZnO） heterojunction bilayers grown on ITO substrate by pulsed laser deposition ...A novel photovoltaic phenomenon of internal photoemission was found in a low cost manganite La0.62Ca0.29K0.09MnO3 （LCKMO）/zinc oxide （ZnO） heterojunction bilayers grown on ITO substrate by pulsed laser deposition （PLD） at relative low growth temperature. The heterostructure ITO/LCKMO/ZnO/A1 exhibits reproducible rectifying characteristics and light cur- rent under continuous laser irradiation of 2 = 325 nm. We report here the influence of LCKMO/ZnO bilayers＇ thickness on the electrical and photoelectric properties of the heterostructure at room temperature. The power conversion efficiency （PCE） is achieved when the LCKMO and ZnO layers are thin enough or the full space charge layer is sufficient. We obtained the maximum value of PCE of 0.0145% when the thicknesses of LCKMO and ZnO layers are 25 and 150 nm, respectively. The open circuit voltage is 0.04 V under this condition due to the internal photoemission.展开更多
基金Foundation item: Projects(50571059, 50615024 ) supported by the National Natural Science Foundation of ChinaProject(NCET-07-0536) supported by Program for New Century Excellent Talents in UniversityProject(IRT0739) supported by Program for Innovative Research Team in University
文摘Deep level donor＇s ionization behavior of passive film formed on the surface of stainless steel was investigated by Mott-Schottky plots. It is indicated that transformation process of deep level donors＇ ionization behavior of passive film on surface of stainless steel can be divided into 4 stages with rising immersion time. At the initial immersion stage （10 min）, Fe（II） located in the octahedral sites of the unit cell is not ionized and the deep level does not appear in Mott-Schottky plots. At the second stage （9-38 h）, Fe（II） located in the octahedral sites starts to be ionized, which results in deep level donors＇ generation and density of deep level donors almost is constant with augmenting immersion time but the thickness of space charge layer is more and more thicker with rising immersion time. At the third stage （48 h-12 d）, density of deep level donors rises with increasing immersion time and the thickness of passive films space charge layer decreases. At last stage （above 23 d）, both the space charge layer＇s thickness and density of deep level donors are no longer changed with increasing immersion time. In the overall immersion stage, the shallow level donors＇ density is invariable all the time. The mechanism of deep level donor＇s ionization can be the generation of metal vacancies, which results in crystal lattice＇s aberration and the aberration energy urges the ionization of Fe（ II ） in octahedral sites.
基金supported by the National Natural Science Foundation of China (No. 90922034 and No. 21131002)Specialized Research Fund for the Doctoral Program of Higher Education (No. 20110061130005)
文摘A novel photovoltaic phenomenon of internal photoemission was found in a low cost manganite La0.62Ca0.29K0.09MnO3 （LCKMO）/zinc oxide （ZnO） heterojunction bilayers grown on ITO substrate by pulsed laser deposition （PLD） at relative low growth temperature. The heterostructure ITO/LCKMO/ZnO/A1 exhibits reproducible rectifying characteristics and light cur- rent under continuous laser irradiation of 2 = 325 nm. We report here the influence of LCKMO/ZnO bilayers＇ thickness on the electrical and photoelectric properties of the heterostructure at room temperature. The power conversion efficiency （PCE） is achieved when the LCKMO and ZnO layers are thin enough or the full space charge layer is sufficient. We obtained the maximum value of PCE of 0.0145% when the thicknesses of LCKMO and ZnO layers are 25 and 150 nm, respectively. The open circuit voltage is 0.04 V under this condition due to the internal photoemission.
