Investigation of Interfacial Charge Separation at PbS QDs/(001) TiO<sub>2</sub> Nanosheets Heterojunction Solar Cell

نویسندگان

  • Elham Ghadiri
  • Bin Liu
  • Jacques - E. Moser
  • Michael Grätzel
  • Lioz Etgar
چکیده

In the recent years, the heterojunction solar cells based on quantum dots (QDs) have attracted attention due to strong light absorbing characteristics and the size effect on the bandgap tuning. This paper reports on the kinetics of interfacial charge separation of PbS QDs/(001) TiO 2 nanosheets heterojunction solar cells. PbS QDs are deposited using a bifunctional linker molecule on two different TiO 2 fi lms, i.e., TiO 2 nanosheets (with 001 dominant exposed facet) and TiO 2 nanoparticles (with 101 dominant exposed facet). Upon bandgap excitation, electrons are transferred from the PbS QDs conduction band to the lower lying conduction band of TiO 2 . Based on the ultrafast pump-probe laser spectroscopy technique, the kinetics of charge separation is scrutinized at the PbS/TiO 2 interface. The interfacial charge separation at PbS/TiO 2 nanosheets fi lms made of (001) dominant exposed facets is fi ve times faster than that on (101) dominant exposed facets TiO 2 nanoparticles. The quantum yields for charge injection are higher for the (001) TiO 2 nanosheets than the (101) TiO 2 nanoparticles due to enhanced interfacial interaction with (001) surface compared to the (101) nanoparticles. The superior interfacial charge separation at PbS/(001) nanosheets respect to PbS/(101) nanoparticles is consistent with the higher photocurrent and enhanced power conversion effi ciency in the PbS QDs/(001) TiO 2 heterojunction solar cell. The use of (001) TiO 2 nanosheets can be a better alternative to conventional mesoporous TiO 2 fi lms in QD heterojunction solar cells and perovskites-based heterojunction solar cells. region. PbS QDs have high dielectric constant, small electron, and hole effective mass and large Bohr radius of 18 nm. [ 1–3 ]

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Photovoltaic Performance of Dye-Sensitized Solar Cell (DSSC) Fabricated by Silver Nanoclusters-Decorated TiO2 Electrode via Photochemical Reduction Technique

In this investigation, Ag@TiO2 nanocomposite was prepared by deposition of silver nanoclusters onto commercial TiO2 nanoparticles (known as P25 TiO2) via photodeposition technique as clean and simple photochemical route. The synthesized Ag@TiO2 nanocomposite was utilized in the fabrication of dye-sensitized solar cell (DSSC) chiefly because, compared ...

متن کامل

Ab Initio Simulation of Charge Transfer at the Semiconductor Quantum Dot/TiO<sub>2</sub> Interface in Quantum DotSensitized Solar Cells

Quantum dot-sensitized solar cells (QDSSCs) have emerged as a promising solar architecture for next-generation solar cells. The QDSSCs exhibit a remarkably fast electron transfer from the quantum dot (QD) donor to the TiO 2 acceptor with size quantization properties of QDs that allows for the modulation of band energies to control photoresponse and photoconversion effi ciency of solar cells. To...

متن کامل

Reduced Carrier Recombination in PbS - CuInS2 Quantum Dot Solar Cells

Energy loss due to carrier recombination is among the major factors limiting the performance of TiO2/PbS colloidal quantum dot (QD) heterojunction solar cells. In this work, enhanced photocurrent is achieved by incorporating another type of hole-transporting QDs, Zn-doped CuInS2 (Zn-CIS) QDs into the PbS QD matrix. Binary QD solar cells exhibit a reduced charge recombination associated with the...

متن کامل

Investigation and characterization of TiO2-TFC nanocomposite membranes; membrane preparation and UV studies

The purpose of this study was to compare the presence or absence of UV irradiation on the separation performance and morphology of the TiO2-assembled thin film membranes (in different concentrations). Furthermore, an attempt was made to show and compare the effect of the presence of TiO2 nanoparticles in aqueous and organic phases during the interfacial polymerization proc...

متن کامل

Restricted charge recombination process in PbS quantum dot sensitized solar cells by different coating cycles of ZnS films

The relatively low power conversion efficiency (PCE) of quantum dot sensitized solar cells (QDSSCs) is attributed to charge recombination at the interfaces. Charge recombination process could be suppressed by coating the QD layer with a wide band gap semiconductor such as ZnS, which acts as a blocking layer between the QDs and hole transport material (HTM). In present study, to improve PCE of P...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2015