13:30 〜 15:30
▲ [9p-PA1-19] Electrical and optical properties of Zn3N2 thin films
キーワード：Nitride thin film, Photovoltaic absorber
Nitrides are an interesting family of inorganic compounds for various applications. Zn3N2 is one of the attractive n-type nitrides with special interest, as it is composed of only earth-abundant elements. A direct band gap of 0.84 eV predicted by theoretical calculations indicates that it could be promising candidate for thin film photovoltaic absorber with the characteristics of being “ultra-low-cost” [1,2]. In addition, the computedly effective mass of electron is as small as 0.08 mo (mo is the free electron mass), implying that the high mobility is expected [2]. However, most of the reported results show the degenerate properties of Zn3N2 thin films with the room temperature carrier concentration of 1018 – 1020 cm-3.
In this work, Zn3N2 thin films have been grown on glass and MgO (100) substrates by UHV magnetron sputtering. Their electrical and optical properties have been investigated. It is seen that heating on the substrate during the deposition can influence the carrier concentration remarkably, as shown in Fig. 1. Intentional heating on the substrate will increase the carrier concentration, while no intentional heating is beneficial to suppress the carrier concentration, giving rise to non-degenerate properties. Room temperature carrier concentration and mobility of Zn3N2 thin films without intentional heating are 1.5 x 1017 cm-3 and 58 cm2/Vs, respectively. The mechanism behind this tunable properties will be discussed. Finally, the optical properties of Zn3N2 thin films will be presented.
In this work, Zn3N2 thin films have been grown on glass and MgO (100) substrates by UHV magnetron sputtering. Their electrical and optical properties have been investigated. It is seen that heating on the substrate during the deposition can influence the carrier concentration remarkably, as shown in Fig. 1. Intentional heating on the substrate will increase the carrier concentration, while no intentional heating is beneficial to suppress the carrier concentration, giving rise to non-degenerate properties. Room temperature carrier concentration and mobility of Zn3N2 thin films without intentional heating are 1.5 x 1017 cm-3 and 58 cm2/Vs, respectively. The mechanism behind this tunable properties will be discussed. Finally, the optical properties of Zn3N2 thin films will be presented.