Energy position of near-band-edge emission spectra of InN epitaxial layers with different doping levels

Understanding the role of Si doping on surface charge and optical properties: Photoluminescence study of intrinsic and Si-doped InN nanowires

“…This small activation energy is consistent with the derived exciton binding energy ∼ 2 − 3 meV if assuming InN dielectric constant ǫ ∼ 14, and effective mass for electron m * e = 0.05m 0 and for hole m * h = 0.3m 0 . 6,41,58,59 These studies suggest the recombination process changes from free-exciton emission at low temperatures to electron-hole plasma emission at high temperatures in the presented undoped InN nanowires. Such measurements were also performed on undoped InN nanowires with lengths up to ∼ 4 µm, which show similar scaling behavior (see open triangles in Fig.…”

“…8,21,33 It should be noted that the PL peak energy in general is not equivalent to bandgap energy; it is only approximately valid when under very low excitation conditions and in the absence of localized states and band-tailing effect. 6 Table I shows the extracted E g (0), α, and β values measured under different optical excitation conditions, and with different nanowire lengths. It can be seen that in the lowest photo-generated carrier density regime (with 0.8 µm nanowire length, 1 mW excitation power, and 50 µm beam size), E g (0) is ∼ 0.672 eV; this value is consistent with the smallest reported E g (0) in InN epi-layers.…”

“…InN, after being discovered of a narrow bandgap (E g ∼ 0.65 − 1 eV) [1][2][3][4][5][6][7][8][9][10][11][12][13][14] and predicted to possess the largest electron mobility among group-III nitrides (∼ 4400 cm 2 ·V −1 ·s −1 at 300 K), 15 has emerged as a highly promising material for infrared photodetectors and lasers, solar cells, ultrahigh-speed transistors, and sensors. [16][17][18] To date, however, the practical device applications of InN-based materials have been severely limited by the presence of extremely large residual electron density and the uncontrolled surface charge properties, as well as the difficulty in achieving p-type conductivity.…”

Low-field electron mobility in wurtzite InN

“…22). Bearing in mind that m * is inversely proportional to 0 μ and that an effective electron mass for InN between 0.04×m 0 and 0.05×m 0 (note the value of 0.04×m 0 used by us) has been recently established, [23][24][25] the mobilities predicted in this work seem to be realistic.…”

High carrier concentration induced effects on the bowing parameter and the temperature dependence of the band gap of GaxIn1−xN

“…Therefore, the experimental data need to be interpreted more carefully by taking into account of the high carrier concentration effects. [6][7][8][9][10] The aim of the current work is, therefore, to study the band parameters in Ga x In 1Àx N alloys with Ga fraction of x ¼ 0.019, 0.062, 0.324, 0.52, 0.56 as a function of the free carrier concentration using photoluminescence (PL) and Hall Effect measurements. The effects of the high free carrier concentration are considered using the "free-to-bound" recombination model, taking into account the conduction band (CB) non-parabolicity, bandgap renormalization due to many-body effects and formation of localized states above the valence band (VB) edge.…”