Table 1
EDX data for BixSe1−x system
Composition | Bulk | Thin film | ||
|---|---|---|---|---|
Se [at.%] | Bi [at.%] | Se [at.%] | Bi [at.%] | |
Bi5Se95 | 94.96 | 5.04 | 94.79 | 5.21 |
Bi10Se90 | 90.39 | 9.61 | 90.03 | 9.97 |
Fig. 1
XRD patterns of Se, Bi5Se95 and Bi10Se90 thin films.
Fig. 2
AFM images of Se, Bi5Se95 and Bi10Se90 thin films.
Fig. 3
Temperature dependence of DC conductivity of all studied films.
Fig. 4
log(σ(Ω -1 •cm -1)) vs. T -1/4 for all films indicating the variable range hopping conduction.
Table 2
DC electrical parameters of BixSe1−x system.
Composition | ΔEσ[eV] | σo[Ω.cm] −1 | ΔE1 [eV] | σ1 [Ω.cm] −1 |
|---|---|---|---|---|
Se | 0.99±0.12 | 3.9 × 1010 | 0.87±0.04 | 3.3 × 1011 |
Bi5Se95 | 0.03±0.03 | 0.69 | 0.12±0.002 | 0.2 × 102 |
Bi10Se90 | 0.14± 0.02 | 0.8 × 103 | 0.09± 0.004 | 0.15 × 103 |
Table 3
DC electrical parameters of BixSe1−x system
Composition | A K1/4 | To K | σho Ω−1.cm−1 | α cm−1 | N(Ef) eV−1.cm−3 | Rh cm | W me V | αR |
|---|---|---|---|---|---|---|---|---|
Se | 20.65 | 1.8 × 105 | 2 × 102 | 2 × 106 | 1.021 × 1021 | 3 × 107 | 8 | 8.8 × 102 |
Bi5Se95 | 7.21 | 2.7 × 103 | 0.1 × 102 | 1.4 × 104 | 6.87 × 1022 | 3.6 × 10−7 | 0.075 | 0.6 |
Bi10Se90 | 5.61 | 9.9 × 102 | 8.1 × 10 | 5.7 × 104 | 1.87 × 1023 | 2 × 10−7 | 0.15 | 2.8 |
Fig. 5
Absorption spectra of all studied films.
Fig. 6
Relation between (αh⋎)1/2 and photon energy hv for all studied films.
Table 4
Values of optical parameters of BixSe1−x system
Composition | ET eV | Ee eV | B1/2 (eV.cm)−1/2 |
|---|---|---|---|
Se | 1.8±0.05 | 0.2±0.01 | 978.72 |
Bi5Se95 | 0.87±0.05 | 0.21±0.03 | 655.27 |
Bi10Se90 | 0.65±0.05 | 0.52±0.03 | 245.38 |
Fig. 7
Absorption spectra for as-deposited Se thin film and Se thin film γ-irradiated with different doses.
Fig. 8
Absorption spectra for as-deposited Bi5Se95 thin film and Bi5Se95 thin film γ-irradiated with different doses.