Ab initio study on the effect of structural relaxation on the electronic and optical properties of P-doped Si nanocrystals

Abstract

A density functional theory-based study of the electronic structures and properties of cage like metal doped silicon clusters J. Appl. Phys.

Modulation of surface states by phosphorus to improve the optical properties of ultra-small Si nanocrystals

“…After adding a few P atoms into Si NCs/SiO 2 multilayers (0.2%), the EX center defect signal became weak, which indicates the reduction of EX center concentration on the interfaces due to the passivation effect of P dopants located at the NCs surfaces. For the high P-doped sample (4%), a strong signal of conductor electrons is detected with a g value of 1.998, which attributes to partly P impurities located at the Si NCs lattice sites substitutionally providing free electrons [36][37][38][39].…”

Density functional theory study on the B doping and B/P codoping of Si nanocrystals embedded in SiO2

“…Therefore, the similar preferential distribution of B and codoped B/P should occur as the NC size changes from 1.4 nm to a different one. It has been shown that the electronic structures of doped Si NCs critically depend on the doping-induced structural distortion [38,47]. When the NC size is 1.4 nm, Si NCs are less vulnerable to structural distortion [58][59][60].…”

“…Formation energy Figure 1 shows the model of a geometry-optimized 1.4-nm Si NC embedded in SiO 2 with (a) perfect Si/SiO 2 interface (Si@SiO 2 ) or (b) defective Si/SiO 2 interface at which a Si dangling bond exists (Si@ db SiO 2 ). The model of Si@SiO 2 is based on a 1.4-nm H-passivated Si NC (Si@H, Si 71 H 84 ), which has been detailed in our previous work [43][44][45][46][47]. An O atom is used to replace every H atom in SiH and SiH 3 at the surface of Si@H, which is then outwardly bonded to an added Si atom.…”

Ab Initio Study of Donor and Acceptor Ground States in the P–B Codoped Si Nanostructures

“…In ref , it was shown that the formation energy of a single-Boron-doped nanostructure becomes saturated at the sizes larger than Si 147 H 100 . In ref , the formation energy of a Si nanostructure (Si 71 H 84 ) doped with 3 phosphorus dopants was 2.35 and 2.48 eV, respectively, for the cases without and with relaxation introduced by geometry optimization. The 0.13 eV binding energy difference (∼5%) between relaxed and unrelaxed structures was very small for such heavily doped systems.…”

“…Typically, 10 Å of vacuum separation was used in the cluster simulations reported elsewhere. 20 The dimensions of the unit cell are about 54 Å × 43 Å × 32 Å. The dimensions of the nanorod are about 34.3 Å × 23.4 Å × 12.5 Å, as indicated in Figure 1.…”