Coupled semiconductors

Fig. 5.17 CdS-ZnO coupled semiconductor system (a) interaction between two colloidal particles showing the principle of the charge injection process and (b) light absorption and electron transfer on an electrode surface leading to the generation of photocurrent. (Reproduced from [330])...

Hotchandani S, Kamat P (1992) Charge-transfer processes in coupled semiconductor systems. Photochemistry and photoelectrochemistry of the colloidal cadmium sulfide-zinc oxide system. J Phys Chem 96 6834—6839... 

Fig. 7.9 Schematic representation of the energy levels of CdS-Ti02 coupled semiconductor showing the charge transfer process.

Composite semiconductor nanoclusters can be classified into two categories, namely, capped- and coupled-type heterostructures. The capped nanoclusters essentially have a core-shell geometry while in a coupled system two semiconductor nanoclusters are in contact with each other. The principle of charge separation in capped and coupled semiconductor systems is illustrated in Fig. 12. 

Vinodgopal, K. Kamat, P. V. Enhanced rates of photocatalytic degradation of an azo dye using SnOj/TiOj coupled semiconductor thin films, Environ. Sci. Technol. 1995, 29, 841. 

Serpone, N. Maruthamuthu, P. Pichat, P. Pelizzetti, E. Hidaka, H. Exploiting the interparticle electron transfer process in the photocatalyzed oxidation of phenol, 4-chlorophenol and pentachlorophenol Chemical evidence for electron and hole transfer between coupled semiconductors, J. Photochem. Photobiol., A Chem. 1995, 85, 247. 

Fig. 16.16 Energy level diagram of quantized TiOj/C dS coupled semiconductors [Sant and Kamat (2002) - Reproduced by permission of the PCCP Owner Societies]...

Kumar, A. and A.K. Jain (2001). Photophysics and photochemistry of colloidal CdS-Ti02 coupled semiconductors - photocatalytic oxidation of indole. Journal of Molecular Catalysis A-Chemical, 165(1-2), 265-273. 

Figure 11. Photo-induced charge separation in composite semiconductor particles (a) capped and (b) coupled semiconductor nanocrystallites. Photo-generated charge carriers move in opposite directions.

The following system is widely used (cf. Refs. [6, 7, 12]) for describing the dynamics of two face to face coupled semiconductor lasers ... 

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