[18p-PA5-1~22] 6.4 Thin films and New materials

▲ [18p-PA5-14] Formation of pn junction using α-MnTe/AZO stack structure for new photovoltaic and electronic applications

〇(M1)Mihyeon Kim¹, Shunsuke Mori¹, Daisuke Ando¹, Yuji Sutou¹ (1.Tohoku Univ.)

Keywords:pn heterojunction, photovoltaic materials, electronic thin films

The pn junction forms the basis of semiconductor technology and it is one of the simplest semiconductor devices that has been used for many kinds of applications; solar cells to convert light energy to electronic power and selector devices to access memory cells. It is well known that most pn diode devices are composed of Si, however, as Silicon devices pushed to their limits, the development of new semiconductor-compound materials are expected for next generation. We focus on a chalcogenide material, namely Manganese Telluride. Recently, it has been reported that it has proper energy band gap for light absorber layer of solar cells. MnTe showing p-type semiconductor is expected to be applied for various pn-junction semiconductor devices. Here, we focus on Al-doped Zinc Oxide, called AZO, as n-type semiconductor. AZO is well known for its non-toxicity, and low-production cost. The formation of pn junction between AZO and α-MnTe can be expected from following 3 features; their semiconductor types, structural similarity, and suitable energy band gaps for use as solar cells. α-MnTe/AZO stack structures were deposited on the thermal-SiO₂(725µm)/Si(100nm) substrate with by RF magnetron sputtering. As a result, pn diode characteristics were obtained in the stack structure. And AZO(330nm, N_d:6.51*10¹³cm^-3)/α-MnTe (500nm, N_d:5.56*10²⁰cm^-3) showed the diode function with the ideality factor of 6.62.