Interfacial electron transfer mechanisms in bithiophene sensitized TiO2 based solar cells

Abstract

Kinetic studies at Ti0 2 /bithiophene/electrolyte interfaces were conducted, and their parameters to the solar cell functions were related. The solar cell based upon the bithiophene sensitised Ti0 2 films resulted in the maximum IPCE of approximately 25 % at 400 nm. Comparison of emission studies between the bithiophene adsorbed Ti0 2 and Alz0 3 revealed the electron injection from the excited bithiophene into the Ti0 2 with the efficiency of nearly 100 %. The charge recombination between the bithiophene cation and the electron in the Ti0 2 appeared to be fast with a half decay time of 70 J.lS in comparison to the ruthenium dye sensitized Ti0 2 film (~1 ms). The bithiophene regeneration rate with the half time of 20 J.lS was slightly faster, clarifying the inferior photocurrent performance.

Charge Recombination Kinetics at an in Situ Chemical Bath-Deposited CdS/Nanocrystalline TiO2 Interface

“…The measurements were repeated for three different samples on each CdS coating. Submicrosecond to millisecond transient absorption studies were conducted by a home-built transient absorption spectrometer with a Nd/YAG laser (Spectra Physics, Quanta-Ray GCR-11) pumped dye laser (Usho Optical Systems, DL-100, ∼10 ns pulse duration) as a pump source, a 100 W tungsten lamp as a probe source, a photodiode-based detection system (Costronics Electronics), and a TDS-2022 Tektronix oscilloscope . All transient data were collected by confirming identical excitation homogeneity and density of absorbed photons for all samples.…”

“…Submicrosecond to millisecond transient absorption studies were conducted by a home-built transient absorption spectrometer with a Nd/YAG laser (Spectra Physics, Quanta-Ray GCR-11) pumped dye laser (Usho Optical Systems, DL-100, ∼10 ns pulse duration) as a pump source, a 100 W tungsten lamp as a probe source, a photodiode-based detection system (Costronics Electronics), and a TDS-2022 Tektronix oscilloscope. 22 All transient data were collected by confirming identical excitation homogeneity and density of absorbed photons for all samples. An excitation wavelength was selected to 425, 480, 500, 515, and 520 nm for CdS-5, -10, -15, -20, and -25/TiO 2 , respectively, shown as arrows in Figure 1 (absorbance: approximately 0.4 after the baseline subtraction).…”

Organic conducting wire formation on a TiO2 nanocrystalline structure: towards long-lived charge separated systems

“…The charge separated state at the F1BT2H/TiO 2 or P-F1BT2/TiO 2 interface was monitored by transient absorption spectroscopy. 13 The transient spectrum obtained for P-F1BT2/TiO 2 was further analyzed by comparing the polymer cation spectra generated with the spectroelectrochemical method (see ESIw). 14 The spectrum obtained by applying +0.7 V vs. Ag/AgCl to P-F1BT2/TiO 2 is almost identical with the P-F1BT2/TiO 2 transient spectrum, as shown in Fig.…”

Reversible Photoelectrochromism of poly-N-methyl pyrrol /TiO2 Nanohybrid Films

“…We further demonstrated that the interfacial structural control is the key to function the device by transient absorption spectroscopy. 2 In this presentation, we attempt to verify novel functions of the nanohybrid films by applying to photoelectrochromic devices. A model system as in Fig 2 is considered.…”