초록 |
Organic-inorganic perovskite materials have some advantages for optoelectronic applications. They have direct band-gap, large absorption coefficient (ε) of ≈ 104 cm-1, low exciton binding energy, long charge diffusion length, high charge carrier mobility and solution porcessability, optical-gap tunability. The perovskite materials with above properties have advantage for apply to broad-band photodetector. These properties induce high specific detectivities, large linear dynamic range and high response frequency. However, the property of low exciton binding energy can also make disadvantage for photodetector performance, especially, responsivity and detectivity. This property can make exciton to easily separate in ambient condition. It induce high dark-current which makes the low responsivity and detectivity. To lower the dark-current, we use very thin insulating polymer layer as hole-blocking layer. So, we can fabricate perovskite photodetector with high responsivity and detectivity. |