Density of states in Bi₁₂TiO₂₀from time-of-flight measurements

Abstract

Two sillenite crystals of Bi12TiO20, one intrinsic and one lead doped, have been studied by means of the time-of-flight (TOF) experiment. After a short presentation of the technique, we return to the different methods proposed to extract the transit time from the current transients recorded with the TOF experiment. Further, we illustrate the possibility of extracting the density of states from these transients by means of a Laplace transform applied to the variation with time of the transient currents. Then we present some experimental results. The room temperature drift mobilities we measured were equal to 2 and 0.2 cm2 V−1 s−1 for the lead doped and intrinsic sample, respectively. Finally we present the densities of states found for each crystal and compare them to the results obtained from modulated photocurrent experiments applied to the same samples.

Preparation of Binary Type II α-Bi2O3/Bi12TiO20 Cross-Shaped Heterojunction with Enhanced Visible Light Photocatalytic Performance

“…Comparatively, the conduction band (CB) position of BTO was more negative, and the valence band (VB) position of BO was more positive. Hence, according to the fact that pure BTO and BO both were p-type conductivity, it can be concluded that the produced BBTO composite was an interleaved type II and p–p heterojunction. ,,− Such energy band arrangement favored the separation of carriers in BBTO and promoted the photocatalytic efficiency. , …”

“…It is known that the stability and reusability of a photocatalyst have been the focus for their applications. ,− Figure d shows the RhB photodegradation by the BBTO photocatalyst after six cycles with visible light irradiation, where its photocatalytic activity was largely maintained after six successive runs.…”

Deconvolution of the transient photocurrent signals: application to the study of the density of states of a BTO crystal

“…Finally, we also want to underline that the peak indicated by an arrow was detected from a time of flight experiment performed on the same crystal with the same wavelength as we used for the TPC [7].…”