Abstract :
We focus on the time response of photovoltage property in heterojunction composed of univalent doped manganite La0.9Li0.1MnO3(LIMO) and SrTiO3–Nb(STON). Under the irradiation of 248 nm laser pulse, the photovoltage shows a second order exponential rising process with time constants τ1(=27.7–93.0 μs) and τ2 (<9.84 μs). After the light source is shut down, the photovoltage exhibits a first order exponential decreasing stage. The carrier lifetime τ at the order of millisecond in this p–n junction is much longer than that in similar p–n junctions based on manganites. The maximum values of both τ1 and τ appear at around 250 K, which coincides with the metallic-insulator transition temperature for LIMO. These imply that the time response property of heterojunction is partly controlled by the inherent transportation mechanisms in the LIMO layer.
