A novel photovoltaic phenomenon of internal photoemission was found in a low cost manganite La0.62Ca0.29K 0.09MnO3 (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/Al exhibits reproducible rectifying characteristics and light current under continuous laser irradiation of = 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.
以MnO2,Ca(OH)2和La(OH)3为反应原料,在惰性气氛、低温(500℃)熔融KOH体系中合成了具有菱形钙钛矿结构Ca,K共掺杂的La0.64Ca0.25K0.11MnO3纳米材料,并对Mn的价态及磁学性能等进行了讨论.X射线光电子能谱(XPS)分析结果表明,La0.64Ca0.25K0.11MnO3纳米材料中的Mn具有三重混合价态,其零场冷却低温磁化率曲线表现出顺磁-铁磁转变,居里温度(Tc)为280 K.
Epitaxial growth of SmFeO3/SrRuO3 was achieved on SrTiO3 substrates by the pulsed laser deposition(PLD)method at 973 K under oxygen partial pressure of 12.5 Pa.No Fe2+leakage was detected in our SmFeO3 film.The remanent polarization and coercive electric field of the thin film with a higher degree of orientation along(110)were 1.97μC/cm2 and 0.89×104 V/cm at room temperature,respectively.This film showed enhanced canted antiferromagnetism spin ordering compared with its corresponding powder materials.
采用脉冲激光沉积法在单晶SrTiO3(STO)基底上制备了La0.62Ca0.29K0.09MnO3(LCKMO)薄膜,通过调控基底温度获得了平整致密的膜层.利用二维面探X射线衍射仪和高分辨透射电子显微镜对薄膜结构进行了表征.结果表明,薄膜呈高质量取向外延生长,对应关系为{001}LCKMO||{001}STO.对薄膜的磁热性能研究表明,5 T下最大磁熵变为3.45 J/(kg·K),相对制冷效率为379.5 J/kg,磁熵半峰宽为110 K.
