Crystal Structure
Fractional Coordinates | Orthogonal Coordinates | |||||||
---|---|---|---|---|---|---|---|---|
Label | Elmt | x | y | z | xor[Å] | yor[Å] | zor[Å] | |
1. | T1 | Cd | 0.6667 | 0.3333 | 0.0000 | -1.738 | -0.109 | 1.768 |
2. | T1 | Cd | 0.3333 | 0.6667 | 0.5000 | 0.824 | 3.199 | 2.747 |
3. | T1 | Cd | 0.6667 | 0.3333 | 1.0000 | -1.415 | 6.859 | 2.513 |
4. | T2 | Se | 0.6667 | 0.3333 | 0.3750 | -1.617 | 2.504 | 2.048 |
5. | T2 | Se | 0.3333 | 0.6667 | 0.8750 | 0.945 | 5.812 | 3.027 |
Theoretical diffraction data using a Cu Kα monochromatic source.
(m is the multiplicity and N is the maximum number of flexions)
ref no. | h | k | l | d(hkl) | 2-Theta | Intensity | I/Imax | m | N |
---|---|---|---|---|---|---|---|---|---|
[1] | 0 | 1 | 0 | 3.72261 | 23.8828 | 2.01941e-001 | 100.0 | 6 | 1 |
[2] | 0 | 0 | 2 | 3.50760 | 25.3704 | 1.19461e-001 | 59.2 | 2 | 4 |
[3] | 0 | 1 | 1 | 3.28831 | 27.0935 | 1.53355e-001 | 75.9 | 12 | 2 |
[4] | 0 | 1 | 2 | 2.55288 | 35.1217 | 7.60123e-002 | 37.6 | 12 | 5 |
[5] | 1 | 1 | 0 | 2.14925 | 42.0016 | 1.76915e-001 | 87.6 | 6 | 2 |
[6] | 0 | 1 | 3 | 1.98014 | 45.7830 | 1.76516e-001 | 87.4 | 12 | 10 |
[7] | 0 | 2 | 0 | 1.86131 | 48.8904 | 2.81154e-002 | 13.9 | 6 | 4 |
[8] | 1 | 1 | 2 | 1.83259 | 49.7080 | 1.10330e-001 | 54.6 | 12 | 6 |
[9] | 0 | 2 | 1 | 1.79906 | 50.6993 | 2.62001e-002 | 13.0 | 12 | 5 |
[10] | 0 | 0 | 4 | 1.75380 | 52.1043 | 9.71422e-004 | 0.5 | 2 | 16 |
[11] | 0 | 2 | 2 | 1.64416 | 55.8710 | 1.92128e-002 | 9.5 | 12 | 8 |
[12] | 0 | 1 | 4 | 1.58655 | 58.0890 | 1.00406e-003 | 0.5 | 12 | 17 |
[13] | 0 | 2 | 3 | 1.45629 | 63.8640 | 6.32987e-002 | 31.3 | 12 | 13 |
[14] | 1 | 2 | 0 | 1.40701 | 66.3825 | 2.18411e-002 | 10.8 | 12 | 5 |
[15] | 1 | 2 | 1 | 1.37954 | 67.8819 | 2.09435e-002 | 10.4 | 24 | 6 |
[16] | 1 | 1 | 4 | 1.35881 | 69.0623 | 2.22018e-003 | 1.1 | 12 | 18 |
[17] | 0 | 1 | 5 | 1.31289 | 71.8441 | 4.43706e-002 | 22.0 | 12 | 26 |
[18] | 1 | 2 | 2 | 1.30587 | 72.2909 | 1.74150e-002 | 8.6 | 24 | 9 |
[19] | 0 | 2 | 4 | 1.27644 | 74.2329 | 4.40427e-004 | 0.2 | 12 | 20 |
[20] | 0 | 3 | 0 | 1.24087 | 76.7395 | 2.86434e-002 | 14.2 | 6 | 9 |
[21] | 1 | 2 | 3 | 1.20560 | 79.4187 | 6.73141e-002 | 33.3 | 24 | 14 |
[22] | 0 | 3 | 2 | 1.16983 | 82.3607 | 2.45689e-002 | 12.2 | 12 | 13 |
[23] | 0 | 0 | 6 | 1.16920 | 82.4144 | 4.08848e-003 | 2.0 | 2 | 36 |
[24] | 0 | 2 | 5 | 1.12039 | 86.8627 | 2.73303e-002 | 13.5 | 12 | 29 |
[25] | 0 | 1 | 6 | 1.11547 | 87.3415 | 5.39674e-003 | 2.7 | 12 | 37 |
[26] | 1 | 2 | 4 | 1.09748 | 89.1489 | 5.54168e-004 | 0.3 | 24 | 21 |
[27] | 2 | 2 | 0 | 1.07463 | 91.5755 | 1.92663e-002 | 9.5 | 6 | 8 |
[28] | 1 | 3 | 0 | 1.03247 | 96.4951 | 8.94575e-003 | 4.4 | 12 | 10 |
[29] | 2 | 2 | 2 | 1.02749 | 97.1194 | 1.82529e-002 | 9.0 | 12 | 12 |
[30] | 1 | 1 | 6 | 1.02706 | 97.1730 | 1.82418e-002 | 9.0 | 12 | 38 |
[31] | 1 | 3 | 1 | 1.02146 | 97.8876 | 8.99105e-003 | 4.5 | 24 | 11 |
[32] | 0 | 3 | 4 | 1.01296 | 98.9977 | 9.71735e-004 | 0.5 | 12 | 25 |
PV Applications
Basic Parameters at 300 K
Crystal structure: | Wurtzite | 1 |
Group of symmetry: | P6_3mc | 1 |
Number of atoms in 1 cm3: | 3.56*1026 | 1 |
Unit cell volume: | 112.2547 Å3 | 1 |
Atoms per unit cell: | 4 | 1 |
Auger recombination coefficient C: | |||
Debye temperature: | 181.7 K | T = 0 K | 2 |
Density: | 5.81 g/cm3 | T = 300 K | 2 |
Dielectric constants: | ɛ(0)|| = 10.16 | T = 300 K | 2 |
9.29 | T = 100 K | ||
ɛ(0)⊥ = 9.29 | T = 300 K | ||
9.15 | T = 100 K | ||
ɛ(∞)|| = 6.30 | T = 300 K | ||
6.30 | T = 100 K | ||
ɛ(∞) ⊥ = 6.20 | T = 300 K | ||
6.20 | T = 100 K | ||
Effective electron density: | |||
Effective electron masses: | mn = 0.12 m0 | 2 | |
Effective hole density: | |||
Effective hole masses: | mhh = 2.14 m0 | [111] direction | 2 |
0.9 m0 | [100] direction | ||
1.7 m0 | [110] direction | ||
mlh = 0.16 m0 | [111] direction | ||
0.18 m0 | [100] direction | ||
0..16 m0 | [110] direction | ||
mso = 0.12 m0 | split-off band | ||
Lattice constants: | a=b= 4.2985 Å | 1 | |
c = 7.0152 Å |
Band structure and carrier concentration
Temperature Dependences
Temperature dependence on annealed CdSe thin films 3
Thin Films | Crystalite size (Å) | Band Gap 'Eg' (eV) | Electrical resistivity (Ωcm) | Activation energy Ea (eV) | ||
---|---|---|---|---|---|---|
HR | LR | |||||
As-deposited | 40 | 2.3 | 3.25 × 105 | 0.86 | 0.34 | |
373 K | 60 | 2.0 | 9.58 × 104 | 0.79 | 0.31 | |
473 K | 80 | 1.8 | 5.38 × 104 | 0.72 | 0.27 | |
573 K | 120 | 1.8 | 8.23 × 103 | 0.69 | 0.18 | |
673 K | 180 | 1.7 | 1.17 × 103 | 0.65 | 0.16 |
HR: High temperature region LR: Low temperature region
Plot of absorbance vs. wavelength for CdSe thin films can be found in:3
Plot of log ρ vs. (1000/T) of CdSe thin films can be found in: 3
Electrical Properties
Basic Parameters of Electrical Properties
Energy gap: 1.74 eV T = 300 K 2
Energy spin-orbital splitting: 470 meV 2
Intrinsic carrier concentration: 6*1013 cm-3 T = 800 K 2
6*1016 cm-3 T = 1300 K
Carrier mobility: μn = 660 cm2/Vs T = 300 K 2
5000 cm2/Vs T = 80 K
200 cm2/Vs T = 800 K
Electron drift mobility: μdr,n = 720 cm2/Vs T = 300 K 2
Hole Hall mobility: μH,p = 40 cm2/Vs T = 300 K 2
Thermal properties
Heat capacity: Cp [J mol-1 K-1] = 48.46 + 5.87-3 *T – 58154*T-2 2
Thermal conductivity: κL = 0.09 W cm-1 K-1 2
Mechanical properties, elastic constants, lattice vibrations
Basic Parameters
Density: 5.81 g/cm3 T = 300 K 2
Elastic Constants
Elastic Constants: c11 = 74.6 Gpa T = 300 K 2
c12 = 46.1 Gpa
c33 = 81.7 Gpa
c44 = 13.0 Gpa
c66 = 14.3 Gpa
Developed at the University of Utah primarily by undergraduate students Jeff Provost and Carina Hahn working with Prof. Mike Scarpulla. Caitlin Arndt, Christian Robert, Katie Furse, Jash Sayani, and Liz Lund also contributed. The work was fully supported by the US National Science Foundation under the Materials World Network program award 1008302. These pages are a work in progress and we solicit input from knowledgeable parties around the world for more accurate or additional information. Contact [email protected] with such suggestions.
- 1. a. b. c. d. e. f. , “Electronic, optical, and structural properties of some wurtzite crystals”, Physical Review B, vol. 48, no. 7, pp. 4335 - 4351, 1993.
- 2. a. b. c. d. e. f. g. h. i. j. k. l. m. n. o. , Semiconductors Data Handbook. Berlin: Springer, 2004, pp. 815-835.
- 3. a. b. c. , “Influence of air annealing on the structural, optical and electrical properties of chemically deposited CdSe nano-crystallites”, Applied Surface Science, vol. 223, no. 4, pp. 343 - 351, 2004.