An-Najah Staff

IWAM 2010, RAK-CAM/RasalKhayma/2010

The work described here has been done in collaboration with: Rania Ismail, Amer El-Hamouz, Huda Sabri, Subhi Saleh, Maysaa Atatri, Ahed Zyoud, Ghazi Nour, Mosa El-Hasan, Israa Hamdan

Abstract:

In earlier studies, we demonstrated new simple techniques to modify characteristics of monolithic semiconductor electrodes (such as n-Si and n-GaAs) in light-to-electricity conversions. A combination of two methods, namely: cooling rate and coverage with electro-active ions simultaneously enhanced both conversion efficiency and stability of the electrodes.  Due to preparation difficulty and high cost of highly pure monolithic electrodes, research has recently been focused on thin-film semi-conducting (SC) material electrodes, prepared by chemical bath deposition (CBD). However, such thin-film electrodes suffer low efficiency of conversion, and low stability under photo-electrochemical (PEC) conditions. More research is thus needed to modify thin-film electrodes for future PEC applications.

To enhance efficiency and stability of new CBD-based thin-film SC electrodes, we employed our earlier techniques, cooling rate and electro-active species attachment, to cadmium chalcogenide (CdX: where X = S or Se) thin-film electrodes. The results are encouraging. Both electrode efficiency and stability of CdS electrodes have been significantly enhanced. Moreover, CBD-based CdSe films, which have not been described before in PEC systems, has been prepared here and stabilized for the first time ever.

In this presentation, details of preparation, modification, characterization (electronic absorption spectra, fluorescence spectra, XRD and SEM) results and PEC characteristic will be described. Future perspectives of commercializing these results will also be discussed.

References:
1)      H. S. Hilal, M. Masoud, S. Shakhshir, N. Jisrawi, “n-GaAs Band-edge repositioning by modification with metalloporphyrin/polysiloxane matrices” Active and Passive Electronic Components, 26 (2003) 1.
2)      H. S. Hilal, M. Masoud, S. Shakhshir and N. Jisrawi, “Metalloporphyrin/polysiloxane modified n-GaAs surfaces: Effect on PEC efficiency and surface stability”, J. Electroanal. Chem., 527, (2002) 47-55.
3)      H. S. Hilal, I. Sadeddin, S. Saleh, Elisabeth Sellier and G. Campet, Modification of n-Si characteristics by annealing and cooling at different rates, Active and Passive Electronic Components, 26 (2003) 213.
4)      H. S. Hilal, S. Saleh, I. Sadeddin and G. Campet, \"Effect of Annealing and Cooling Rates on n-GaAS Electrode Photoelectrochemical Characteristics\", Active and Passive Electronic Components,  27(2), (2004) 69-80.
5)      H. S. Hilal, W. Ateereh, T. Al-Tel, R. Shubaitah, I. Sadeddin and G. Campet, Enhancement of n-GaAs characteristics by combined heating, cooling rate and metalloporphyrin modification techniques, Solid State Sciences, 6, (2004)139-146.
6)      J. Portier, H. S. HILAL, I. SAADEDDIN, S. J. HWANG and G. Campet, “THERMODYNAMIC CORRELATIONS AND BAND GAP CALCULATIONS IN METAL OXIDES”, Progress in Solid State Chemistry, 32 (2004/5) 207.
7)      H. S. Hilal and J. A. Turner, “CONTROLLING CHARGE-TRANSFER PROCESSES AT SEMICONDUCTOR/LIQUID JUNCTIONS”.  Electrochimica Acta 51 (2006) 6487–6497.
8)      Hikmat S. Hilal, Rania M. A. Ismail, and Amer El-Hamouz, \" Effect of cooling rate of pre-annealed CdS thin film electrodes prepared by chemical bath deposition: Enhancement of photo-electrochemical characteristics”, Electrochemica Acta, 54 (2009) 3433–3440.
9)      Hikmat S. Hilal, Huda Sabri, Iyad Sadeddin, Ahed Zyoud and Subhi Saleh, Photoelectrochemical processes based on FTO/CdSe electrodes prepared by CBD: new techniques to stabilize CdSe electrodes. (Unpublished data, 2009).
10)  Hikmat S. Hilal, Maysaa Jararah, Musa Hassan, Iyad Saadeddin, Preparation, characterization and stabilization of Zn-doped CdS thin film electrodes for photoelectrochemical processes. (Unpublished data 2009).