中国物理B ›› 2020, Vol. 29 ›› Issue (4): 46104-046104.doi: 10.1088/1674-1056/ab7742

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Improved carrier transport in Mn:ZnSe quantum dots sensitized La-doped nano-TiO2 thin film

Shao Li(李绍), Gang Li(李刚), Li-Shuang Yang(杨丽爽), Kui-Ying Li(李葵英)   

  1. State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004, China
  • 收稿日期:2019-12-16 修回日期:2020-01-28 出版日期:2020-04-05 发布日期:2020-04-05
  • 通讯作者: Kui-Ying Li E-mail:kuiyingli@ysu.edu.cn
  • 基金资助:
    Project supported by the Natural Science Foundation of Hebei Province, China (Grant No. E2017203029).

Improved carrier transport in Mn:ZnSe quantum dots sensitized La-doped nano-TiO2 thin film

Shao Li(李绍), Gang Li(李刚), Li-Shuang Yang(杨丽爽), Kui-Ying Li(李葵英)   

  1. State Key Laboratory of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004, China
  • Received:2019-12-16 Revised:2020-01-28 Online:2020-04-05 Published:2020-04-05
  • Contact: Kui-Ying Li E-mail:kuiyingli@ysu.edu.cn
  • Supported by:
    Project supported by the Natural Science Foundation of Hebei Province, China (Grant No. E2017203029).

摘要: Mn:ZnSe/ZnS/L-Cys core-shell quantum dots (QDs) sensitized La-doped nano-TiO2 thin film (QDSTF) was prepared. X-ray photoelectron spectroscopy (XPS), nanosecond transient photovoltaic (TPV), and steady state surface photovoltaic (SPV) technologies were used for probing the photoelectron behaviors in the Mn-doped QDSTF. The results revealed that the Mn-doped QDSTF had a p-type TPV characteristic. The bottom of the conduction band of the QDs as a sensitizer was just 0.86 eV above that of the La-doped nano-TiO2 thin film, while the acceptor level of the doped Mn2+ ions was located at about 0.39 eV below and near the bottom of the conduction band of the QDs. The intensity of the SPV response of the Mn-doped QDSTF at a specific wavelength was ~2.1 times higher than that of the undoped QDSTF. The region of the SPV response of the Mn-doped QDSTF was extended by 191 nm to almost the whole visible region as compared with the undoped QDSTF one. And the region of the TPV response of the Mn-doped QDSTF was also obviously wider than that of the undoped QDSTF. These PV characteristics of the Mn-doped QDSTF may be due to the prolonged lifetime and extended diffusion length of photogenerated free charge carriers injected into the sensitized La-doped nano-TiO2 thin film.

关键词: doping effects, ZnSe quantum dots sensitization, nano-TiO2 thin film, photoelectron spectroscopy

Abstract: Mn:ZnSe/ZnS/L-Cys core-shell quantum dots (QDs) sensitized La-doped nano-TiO2 thin film (QDSTF) was prepared. X-ray photoelectron spectroscopy (XPS), nanosecond transient photovoltaic (TPV), and steady state surface photovoltaic (SPV) technologies were used for probing the photoelectron behaviors in the Mn-doped QDSTF. The results revealed that the Mn-doped QDSTF had a p-type TPV characteristic. The bottom of the conduction band of the QDs as a sensitizer was just 0.86 eV above that of the La-doped nano-TiO2 thin film, while the acceptor level of the doped Mn2+ ions was located at about 0.39 eV below and near the bottom of the conduction band of the QDs. The intensity of the SPV response of the Mn-doped QDSTF at a specific wavelength was ~2.1 times higher than that of the undoped QDSTF. The region of the SPV response of the Mn-doped QDSTF was extended by 191 nm to almost the whole visible region as compared with the undoped QDSTF one. And the region of the TPV response of the Mn-doped QDSTF was also obviously wider than that of the undoped QDSTF. These PV characteristics of the Mn-doped QDSTF may be due to the prolonged lifetime and extended diffusion length of photogenerated free charge carriers injected into the sensitized La-doped nano-TiO2 thin film.

Key words: doping effects, ZnSe quantum dots sensitization, nano-TiO2 thin film, photoelectron spectroscopy

中图分类号:  (III-V and II-VI semiconductors)

  • 61.72.uj
73.63.Kv (Quantum dots) 82.80.Pv (Electron spectroscopy (X-ray photoelectron (XPS), Auger electron spectroscopy (AES), etc.)) 74.78.-w (Superconducting films and low-dimensional structures)