Miranda Alvaro, Cartoixà Xavier, Canadell Enric, Rurali Riccardo
Institut de Ciència de Materials de Barcelona (ICMAB-CSIC), Campus de Bellaterra, BellaterraBarcelona, 08193, Spain.
Nanoscale Res Lett. 2012 Jun 18;7(1):308. doi: 10.1186/1556-276X-7-308.
: The possibility that an adsorbed molecule could provide shallow electronic states that could be thermally excited has received less attention than substitutional impurities and could potentially have a high impact in the doping of silicon nanowires (SiNWs). We show that molecular-based ex-situ doping, where NH3 is adsorbed at the sidewall of the SiNW, can be an alternative path to n-type doping. By means of first-principle electronic structure calculations, we show that NH3 is a shallow donor regardless of the growth orientation of the SiNWs. Also, we discuss quantum confinement and its relation with the depth of the NH3 doping state, showing that the widening of the bandgap makes the molecular donor level deeper, thus more difficult to activate.
与替代杂质相比，吸附分子提供可被热激发的浅电子态的可能性受到的关注较少，但这可能对硅纳米线（SiNWs）的掺杂产生重大影响。我们表明，基于分子的非原位掺杂，即NH3吸附在SiNW的侧壁上，可以成为n型掺杂的另一种途径。通过第一性原理电子结构计算，我们表明，无论SiNW的生长取向如何，NH3都是浅施主。此外，我们讨论了量子限制及其与NH3掺杂态深度的关系，表明带隙变宽会使分子施主能级更深，从而更难激活。
