氧敏化对多晶PbSe薄膜结构和电学性能的影响

Influence of Oxygen Sensitization Process on Structures and Electrical Properties of Polycrystalline PbSe Films

摘要:

利用热蒸发物理气相沉积法在300K的硅基底上制备了p型多晶PbSe薄膜，研究了氧敏化过程对其微观结构和电性能的影响。经XRD、XPS和SEM测试表明，制备的多晶PbSe薄膜为（200）晶面优先生长的面心立方结构，其经高温氧敏化后在微晶表面和晶界处形成了由SeO2和PbO混合氧化物构成的氧化层新相，其微晶会在氧化反应和重结晶的作用下融结在一起，晶粒间间隙会随着退火温度的不断提升而逐渐变小。霍尔效应仪测量表明，常温下沉积的多晶PbSe薄膜为p型，氧敏化未改变其导电类型；随着氧敏化退火温度的增加，其载流子浓度降低，载流子迁移率和薄膜暗电阻不断增大，但实验发现氧敏化过程未提高p型PbSe薄膜的红外光敏性。

Abstract:

The as-grown polycrystalline PbSe thin films were prepared on Si(100) substrates at room temperature by physical vapor deposition (PVD) method, and subsequently annealed at different temperatures in pure oxide. The influences of oxygen sensitization process on p-type PbSe films were studied experimentally. The X-ray diffraction (XRD) pattern showed the predominant growth of crystallites along (200) lattice plane and the appearance of new phase at 26.6° and 27.2° corresponding to PbO and SeO2 compounds after annealing. The X-ray photoelectron spectroscopy (XPS) confirms that PbO and SeO2 were formed as the surface passivation layer covered the PbSe microcrystals. Hall effect measurement showed that the PbSe sample always appear p-type even though oxygen sensitization, and the hole carrier concentration of sensitized PbSe films will decrease, and its mobility and dark resistance will increase with increasing annealing treatment temperature and oxygen passivation. It is noteworthy that no photoelectric response is observed for any p-type PbSe films sensitized by oxygen, which means that oxygen can not trigger photo-response in the sensitization progress for p-type PbSe film.