Wide bandgap semiconductor materials and devices

Photosensitive and Rectifying Properties of Ga2O3 Described by Polaronic Screened Electrons and Internal Potentials

“…Switching the light off again reduces [P 3π ] to its dark density. The short lifetime of the V light and the fast dynamics of the dipolar dissociation in the B 6π /P 3π equilibrium is consistent with the reported high-frequency applications. − ,− …”

“…Their dipole contribution V doping shifts the internal potential Γ (via V π in eq ) and increases the π-electron (P 3π ) concentration within the BiP band. Without changing the limits of N max and N 0 , controllable n-type doping (see Section SI-3) is enabled, and carrier concentrations of up to 10 21 cm –3 can be achieved with high values of V doping . − Here, the PIE model offers a novel aspect as structural and impurity defects are located in the CT band but contribute to the π-electron density only via their dipole moment and not by the thermal ionization of shallow donors/acceptors. Therefore, the PIE model offers a clear way to escape from the dilemma of the complexity of doping in Ga 2 O 3 . − ,− …”

“…In Figure a, we demonstrate the increase of the [B 4π ] by the dipole V pair = 2.5 eV (δΓ = 0.3); it reduces the range of [P 1π ] = [P 3π ] to N π (0.2) [1.6 × 10 11 cm –3 ]. This situation defines the blocking density N blocking , a key feature for Ga 2 O 3 devices such as UV absorbers and rectifiers. − ,− The regimes of the dominant B 2π and B 6π BiPs appear on top of the [P 1π ] = [P 3π ] range (the lower limit of the B 4π level). They exist only when [P 1π ] ≠ [P 3π ] and one of the LaPs dominate, while the concentration of its counterpart is diminished accordingly.…”

“…Currently, there are numerous studies in the literature that aim to understand these mentioned phenomena in a consistent description. Issues are to explain the mechanisms of the high carrier densities, − large photoresponses, − and the absence of p-type carriers, − in particular. Until now, various concepts exist in the literature, which are mostly discussed in terms of an extension of classical physics of tetrahedral (Si, Ge, etc.)…”

“…Until now, various concepts exist in the literature, which are mostly discussed in terms of an extension of classical physics of tetrahedral (Si, Ge, etc.) semiconductors, − although Ga 2 O 3 is an ionic material. The fact that several of the fascinating properties are still unexplained or (controversially) debated points to the need for more sophisticated models that go beyond the conventional concepts of semiconductor and interphase physics and/or leave the restriction of single-particle mechanisms.…”