Characterization of Er in porous Si
- PDF / 1,121,697 Bytes
- 9 Pages / 595.28 x 793.7 pts Page_size
- 107 Downloads / 213 Views
NANO EXPRESS
Open Access
Characterization of Er in porous Si Guido Mula1*, Susanna Setzu1, Gianluca Manunza1, Roberta Ruffilli2 and Andrea Falqui2
Abstract: The fabrication of porous Si-based Er-doped light-emitting devices is a very promising developing field for all-silicon light emitters. However, while luminescence of Er-doped porous silicon devices has been demonstrated, very little attention has been devoted to the doping process itself. We have undertaken a detailed study of this process, examining the porous silicon matrix from several points of view during and after the doping. In particular, we have found that the Er-doping process shows a threshold level which, as evidenced by the cross correlation of the various techniques used, does depend on the sample thickness and on the doping parameters. Keywords: Light-emitting devices, Er doping, Porous silicon, Refractive index PACS: 81.05.Rm, 61.43.Gt, 78.20.-e
Background Efficient and cost-effective Si-based optoelectronic devices are required for all-silicon telecommunication technology [1-3]. The indirect bandgap of silicon, the material of choice for micro- and nanoelectronics, unfortunately forbids luminescence and electro-optic effects, requiring the use of hybrid solutions implying complex and costly techniques [4]. Intense research is then devoted to the study of ways leading to efficient Si-based light-emitting structures that would cancel the need of integrating different materials [1-3]. Several solutions have been explored, from Raman Si laser [5] to Si nanocrystal laser [6,7]. The use of rare earth elements, in particular Er and Yb, for the doping of Si and porous Si [8-10] has been a relevant research field due to the observed room temperature 1.54-μm luminescence. In particular, Er-doped silicon-rich oxide structures showed interesting light-emitting properties [11-14]. Optical gain from Er-doped Si structures at 1.54 μm was also reported [15]. After its discovery [16], porous silicon (PSi) has attracted the interest of researchers when its photoluminescence was observed [17], and many papers were published about its possible applications in optoelectronics [18-20]. However, even if worthy-of-note electroluminescent properties were reported [21], the interest on PSi light-emitting devices faded. When the possibility to obtain light from rare-earth-doped Si structures [11-14] * Correspondence: [email protected] 1 Dipartimento di Fisica, Università degli Studi di Cagliari, Cittadella Universitaria, S.P. 8km 0.700, Monserrato, Cagliari 09042, Italy Full list of author information is available at the end of the article
was proposed, a renewed interest for Er-doped PSi aroused, and remarkable photoluminescent properties [20-23], also from photonic bandgap structures [24,25], were demonstrated. While the emission properties have been studied, together with the Er optical activation process by hightemperature treatments [21], very little attention has been devoted to the doping process itself. For this reason, we present here a study on electroc
Data Loading...
