CuS

Material: CuS

Earth abundance [1]: Good crystals are extremely rare

Basic Info

  • Occurs in nature as the mineral Covellite [1]
  • Usually as indigo-blue massive metallic material [1]
  • Discovered in 1832 [1]
  • Found in copper deposits [1]
  • Named after the Italian mineralogist, N. Covelli (1790-1829) [2]
  • Molecular Weight = 95.61 gm [2]

 

Physical Properties [1]:

Luster:

Sub-Metallic

Diaphaneity (Transparency):

Opaque

Color:

Indigo-blue or darker, inclining towards blue-black, often iridescent with purplish, deep red, and brassy-yellow reflections.

Streak:

Shiny metallic, lead-grey to black

Hardness (Mohs):

1½ - 2

Hardness (Vickers):

VHN100=128 - 138 kg/mm2

Hardness Data:

Measured

Tenacity:

Flexible

Cleavage:

Perfect
Perfect on {0001}.

Fracture:

Irregular/Uneven, Hackly

Density (measured):

4.6 - 4.76 g/cm3

Density (calculated):

4.602 g/cm3

 

Calculated Properties [2]:

 Electron Density:

Bulk Density (Electron Density)=4.41 gm/cc
note: Specific Gravity of Covellite =4.68 gm/cc.

Fermion Index:

Fermion Index = 0.0025153223
Boson Index = 0.9974846777

Photoelectric:

PECovellite = 31.55 barns/electron

 

 

Crystal Structure [1]:

Crystal System:

Hexagonal

Class (H-M):

6/mmm (6/2/2/m) - Dihexagonal Dipyramidal

Space Group:

P63/mmc {P63/2/2/c}

Cell Parameters:

a = 3.7938Å, c = 16.341Å

Ratio:

a:c = 1 : 4.307

Unit Cell Volume:

V 203.7 ų

Z:

6

Morphology:

Hexagonal plates {001}, with pyramidal faces striated horizontally and hexagonal striations on the base. Common forms: {001}, {104}, {103}, {308}, {102}, {9/0/16}, {5.08}, {101} and {201}. Less common to rare: {1.0.16}, {1.0.12}, {3.0.32}, {108}, {106}, {3.0.16}, {105}, {205}, {203}, {304}, {15.0.16} and {908}.

Twinning:

None reported.

 

X-Ray Powder Diffraction Data [1]:

d-spacing

 

Intensity

3.22

 

(30)

3.05

 

(70)

2.81

 

(100)

2.72

 

(60)

2.32

 

(10)

1.90

 

(80)

1.74

 

(40)

1.57

 

(20)

1.56

 

(40)

 

PV Applications:

CuS thin films are deposited bu a chemical bath on top of other thin films such as Sb2S3 [3] and SnS [4]. Then the films are heat treated with Nitrogen and used as an absorber layer [3].

Layer structures were: CuS, SnS, CdS, SnO2 [4] and Sb2S2-CuS, Sb2S3, CdS, TCO [3]

 

 

Band structure and carrier concentration

Band Gap [5]: 1.55 eV

Carrier Concentration [6]: +2.5×1021 cm-3

        Temperature Dependences

A graph showing density of states for CuS vs (E-Ef) (Ryd) can be found at reference 7.

 

Electrical Properties

Conductivity [6]: 2×103 S cm-1

DC resistance [8]: 7.5 × 103 Ω

Resistivity [8]: 2.67 Ω cm

Basic Parameters of Electrical Properties

Electrical conductivity of CuS thin film [5]: 3.6 x 103 Ω-1 cm-1

 

The Hall mobility [6]: 7.24cm2 V-1 s-1 

 

Optical properties [1] :

Type:

Uniaxial (+)

RI values:

nω = 1.450 nε = 2.620

Maximum

δ = 1.170

Surface Relief:

Very High

Type:

Anisotropic

Anisotropism:

Strong

Dispersion:

Strong

Pleochroism:

Visible

Comments:

Deep blue to blue-white

 

Thermal properties

Mechanical properties [8]

        

Scratch resistance [8]: 3 mN

 

References:

[1] J. Ralph, I. Chau, mindat Available at: <http://mindat.org> (2012).

[2] WebMineral, “Covellite Mineral Data”, http://webmineral.com/data/Covellite.shtml#.UmK-dvlvNlJ

 [3] http://www.sciencedirect.com.ezproxy.lib.utah.edu/science/article/pii/S0040609006016129

[4] http://www.sciencedirect.com.ezproxy.lib.utah.edu/science/article/pii/S004060900601604X

[5] http://iopscience.iop.org.ezproxy.lib.utah.edu/0268-1242/13/10/019/pdf/0268-1242_13_10_019.pdf

[6] http://scitation.aip.org.ezproxy.lib.utah.edu/content/aip/journal/apl/93/13/10.1063/1.2991441

[7] http://iopscience.iop.org.ezproxy.lib.utah.edu/0953-8984/4/50/034/pdf/0953-8984_4_50_034.pdf

[8] http://www.sciencedirect.com.ezproxy.lib.utah.edu/science/article/pii/S0025540810004046

 

The development of these pages on photovoltaic materials’ properties was carried out 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 earthabundantpv@eng.utah.edu with such suggestions. Neither the University of Utah nor the NSF guarantee the accuracy of these values.