Porous silicon , electroluminescence

P. Steiner, A. Wiedenhofer, F. Kozlowski, and W. Lang, Influence of different metallic contacts on porous silicon electroluminescence. Thin Solid Films 276, 159, 1996. 

Koshida N, Koyama H, Yamamoto Y, Collins GJ (1993) Visible electroluminescence from porous silicon diodes with an electropolymerized contact. Appl Phys Lett 63(19) 2655-2657 Koshida N, Mizuno H, Koyama H, Collins GJ (1994) Visible electroluminescence from porous silicon diodes with immersed conducting polymer contacts. Jpn J Appl Phys Part 2 34 92-94 Koshida N, Kadokura J, Takahashi M, Imai K (2001) Stabilization of porous silicon electroluminescence by surface capping with silicon dioxide films. MRS Proc 638, F18.13.11. doi 10.1557/ PROC-638-F 18.3.1... 

Simons AJ, Cox Tl, Loni A, Canham LT, Blacker R (1997) Investigation of the mechanisms controlling the stability of a porous silicon electroluminescent device. Thin Solid Films 297(l-2) 281-284... 

Steiner P, Kozlowski F, Lang W (1993) Light-emitting porous silicon diode with an increased electroluminescence quantum efficiency. Appl Phys Lett 62(21) 2700-2702 Steiner P, Kozlowski F, Wielunski M, Lang W (1994) Enhanced blue-light emission from an indium-treated porous silicon device. Jpn J Appl Phys Part 1 33(11) 6075-6077 Steiner P, Wiedenhofer A, Kozlowski F, Lang W (1996) Influence of different metallic contacts on porous silicon electroluminescence. Thin Solid Films 276(1-2) 159-163... 

P. M. Fauchet, Porous Silicon Photoluminescence and Electroluminescent Devices C. Delerue, G. Allan, and M. Lannoo, Theory of Radiative and Nonradiative Processes in Silicon Nanocrystallites L. Bros, Silicon Polymers and Nanocrystals... 

Fauchet PM (1998) Porous silicon photoluminescence and electroluminescent devices. In Semiconductors and semimetals, vol 49. Academic, San Diego, pp 206-252... 

Porous silicon is under extensive study, largely due to its luminescence properties. For electroluminescence, however, some form of contact has to be made with the Si, and this necessitates deposition of another phase inside the pores of the Si in order to contact as much as possible of the internal area of the high-surface-area Si. With this in mind, CdS has been deposited inside the pores of porous silicon via a two-stage method [73]. Cd(OH)2 was deposited from an ammoniacal bath at pH 8, followed by conversion of the Cd(OH)2 to CdS by treatment with thioac-etamide at pH 8. This was repeated several times until the pores were essentially filled with CdS. The reason that this two-stage process was needed is that either the Si was unstable at the temperatures and pH values needed to deposit CdS from a thiourea solution, or CdS was formed in solution rather than on the Si surface using thioacetamide. 

On semiconductors light emission is induced by injection of electrons into the conduction band and subsequent band-to-band radiative recombination with holes (Fig. 38a). The process is reminiscent of electroluminescence or cathodolumines-cence and works with p-type substrates only (at n-type specimens no hole is available at the surface). Tunnel biases of 1.5-2 V are necessary in the case of GaAs, for instance. Figure 38b is a photon map of a GaAlAs/GaAs multiquantum well obtained by Alvarado et al. [140], The white stripes are regions where photons are emitted and correspond to the GaAs layers. The lateral resolution is about 1 nm and is limited by the diffusion distance of minority carriers. In Sec. 5.1 we have seen an example of the application of this technique in the case of porous silicon layers. 

K. Ogasawara, T. Momma, and T. Osaka, Enhancement of electroluminescence from n-type porous silicon and its photoelectrochemical behavior, J. Electrochem. Soc. 142, 1874, 1995. 

A. Halimaoui, Influence of wettability on anodic bias induced electroluminescence in porous silicon, Appl. Phys. Lett. 63(9), 1264, 1993. 

L. T. Canham, W. Y. Leong, M. I. J. Beale, T. I. Cox, and L. Taylor, Efficient visible electroluminescence from highly porous silicon under cathodic bias, Appl. Phys. Lett. 61(21), 2563, 1992. 

G. Bomchil, A. Halimaoui, I. Sagnes, P. A. Badoz, I. Berbezier, P. Perret, B. Lambert, G. Vincent, L. Garchery, and J. L. Regolini, Porous silicon Material properties, visible photo- and electroluminescence, AppZ. Surf. Sci. 65/66, 394, 1993. 

H. Noguchi, T. Kondo, K. Murakoshi, and K. Uosaki, Visible electroluminescence from n-type porous silicon/electrolyte solution interfaces Time—dependent electroluminescence spectra, J. Electrochem. Soc. 146(11), 4166, 1999. 

Luminescence may also arise as a consequence of electrode reactions at semiconductors that result in injection of minority carriers under accumulation conditions (see references in Kelly et al., 1999). An interesting example is the efficient red electroluminescence observed during the reduction of persulphate ions at a porous silicon layer on n-Si (Meulenkamp et al, 1995). Here the luminescence arises from electron/hole recombination, and the holes are injected by the persulphate radical ion according to the scheme... 

Figure 12.19 Voltage-tuned electroluminescence from porous silicon recorded using a CCD spectrograph. Electrolyte 0.2 mol dm Na2S20g + 1.0 mol dm" H2SO4. Adapted from Meulenkamp et al. (1995).

Li K., Diaz D. C., He Y., Campbell J. C., and Tsai C., Electroluminescence from porous silicon with conducting polymer film contacts, Appl. Phys. Lett., 64, 2394-2396,... 

Kleps I, Angelescu A, Miu M (2000) Preparation and characterisation of metallic thin films for electroluminescent devices based on porous silicon. In Nanostructured films and coatings. NATO Science Series, Kluwer, Dordrecht, pp 337-345... 

Fauchet PM (1996) Photoluminescence and electroluminescence from porous silicon. J Lumin 70 294-309... 

Parkhutik V, Chirvony V, Matveyeva E (2007) Optical properties of porphyrin molecules immobilized in nano-porous silicon. Biomol Eng 24(l) 71-73 Pavesi L, Ceschini M, Mariotto G, Zanghellini E, Bisi O, Anderle M, Calliari L, Fedrizzi M, Fedrizzi L (1994) Spectroscopic investigation of electroluminescent porous silicon. J Appl Phys... 

Koshida N, Koyama H (1992) Visible electroluminescence from porous silicon. Appl Phys Lett 60 347... 

Zhang L, Coffer JL, Gnade BE, DaXue X, Pinizzotto RF (1995) Effects of local ambient atmosphere on the stability of electroluminescent porous silicon diodes. J Appl Phys 77 5936 Zimin SP (2000) Classification of electrical properties of porous silicon. Semiconductors 34 353 Zimin SP (2006) Hopping conductivity in low-porosity mesoporous silicon formed on p -Si -B. Semiconductors 40(11) 1350... 

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