First principle study of V-implantation in highly-doped silicon materials

Abstract

Density Functional Theory (DFT) has been used to study structural and electronic properties of new compounds based on V-implanted Si and their potential as infrared photodetectors. Effects derived from the implantation of V on bulk-Si are calculated at different configurations, i.e., substitutional (V Sl ) and interstitial (V,) positions as well as the effect of Si vacancies. Despite all implantation processes are energetically penalized, V,-implanted compound leads to the lowest formation energies. Furthermore, interstitial implantation in the vicinity of a Si vacancy would lead to a highly favored process. The analysis of the electronic structure shows that V r implanted compounds own an intermediate band (due to t 2g states of vanadium atom), which allows new electronic transitions below 1.0 eV. To deal with the bandgap underestimation of common DFT methods, quasiparticle calculations have been applied via the G 0 W 0 approximation. Applied correction to the bandgap based on GW has considerably improved theoretical results compared to experimental ones. The investigation of the absorption features points out that the absorption response can be extended up to infrared region via sub-gap transitions across the intermediate band. This work highlights the potential of V-implanted silicon based materials with infrared response.

Influence of chromium hyperdoping on the electronic structure of CH3NH3PbI3 perovskite: a first-principles insight

“…In this paper, GW calculations were carried out to correct DFT eigenvalues without further interactions, i.e., G 0 W 0 approach 59 , wherein the calculation starts from DFT eigenvalues and eigenfunctions to obtain many-body GW self energy. This method yields successfully agreement with experiment results for intermediate band materials, within the limits of the approach 86 . Since GW approximation is very time consuming, quasi particle energies here reported were only computed for MAPI_48 and Cr@MAPI_48 compounds.…”

Transition Metal-Hyperdoped InP Semiconductors as Efficient Solar Absorber Materials

“…Concretely, GW calculations were carried out to correct the PBE eigenvalues without further interactions, i.e., the G 0 W 0 approach [48], wherein the calculation starts from the DFT eigenvalues and eigenfunctions to obtain many-body GW self-energy. It has been successfully proven that this method yields results that are in good agreement with the experimental results for IGB materials [34,35]. The G 0 W 0 approach was carried out with a Γ-centered 4 × 4 × 4 k-point to sample the Brillouin zone and 512 bands.…”

“…The main goal of this paper is the study of the structural and electronic properties of several TM-hyperdoped InP (TM@InP) compounds in order to find new IGB materials with improved absorption features. Concretely, the selected TM were early 3d-block elements, whose ability to form an IGB has been previously demonstrated [17,20,22,23,25,26,[28][29][30][31][33][34][35][36][38][39][40][41][42][43][44]. Hence, in this work we investigate the structural, stability and electronic properties of several TM@InP (TM = Ti, V, Cr, Mn).…”

“…Although PBE+U formalism would be adequate for the native host material, such an approach has not been applied to in-gap band materials. Our previous works have demonstrated that the many-body perturbation theory in GW approximation (concretely G 0 W 0 approach) [48], yields electronic structure information according to experimental data for other transition metal semiconductors with an in-gap band [24,34,35]. As a result, the electronic structure and optical absorption features were calculated using DFT+U, while G 0 W 0 was used as benchmark method.…”

“…In addition, the IGB must meet some additional requirements to improve its photovoltaic efficiency: (i) have its own small dispersion, without it being at a discreet level; (ii) be well isolated from the VB and CB to avoid thermalization between VB and CB; (iii) be partially filled to allow comparable rates between VB-IGB and IGB-CB transitions; (iv) have high concentrations of IGB states to produce high absorption coefficients for those sub-bandgap absorptions and avoid non-radiative recombination obtained through the formation of a highly delocalized energy band [14-16]. Among the major approaches considered in designing IGB materials, our group have extensively studied the formation of an IGB through the substitutional doping of some cations by a transition metal (TM) [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36]. In this way, the d-orbitals of the TM might be located within the bandgap of the semiconductors, allowing for the formation of an isolated energy band, while the filling of the IGB can be finetuned through the adequate selection of the TM.…”