CADMIUM SELENIDE Property

Melting point:

>1350°C

Density 

5.81 g/mL at 25 °C(lit.)

refractive index 

2.87 (900 nm)

storage temp. 

2-8°C

solubility 

insoluble in H2O

form 

granular

color 

Brown-red to black

Specific Gravity

5.81

Water Solubility 

Insoluble in water.

Sensitive 

air sensitive, store cold

Crystal Structure

Hexagonal, Wurtzite (Zincite) Structure - Space Group P 63mc

Merck 

14,1626

Exposure limits

ACGIH: TWA 0.01 mg/m3; TWA 0.002 mg/m3; TWA 0.2 mg/m3
NIOSH: IDLH 9 mg/m3; IDLH 1 mg/m3; TWA 0.2 mg/m3

Stability:

store cold

CAS DataBase Reference

1306-24-7(CAS DataBase Reference)

EPA Substance Registry System

Cadmium selenide (CdSe) (1306-24-7)

Safety

Hazard Codes 

T,N,Xn,F

Risk Statements 

21-23/25-33-50/53-65-52/53-48/20-38-20/21/22-11-63

Safety Statements 

36/37-45-60-61-28-20/21-62-16

RIDADR 

UN 2570 6.1/PG 3

WGK Germany 

3

RTECS 

EV2300000

TSCA 

Yes

HazardClass 

6.1

PackingGroup 

II

HS Code 

28429090

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Danger

Hazard statements

H312Harmful in contact with skin

H373May cause damage to organs through prolonged or repeated exposure

H410Very toxic to aquatic life with long lasting effects

Precautionary statements

P273Avoid release to the environment.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P301+P310IF SWALLOWED: Immediately call a POISON CENTER or doctor/physician.

P314Get medical advice/attention if you feel unwell.

CADMIUM SELENIDE Chemical Properties,Usage,Production

Chemical Properties

3–12mm pieces (sintered), and -325 mesh 10μm or less with 99.999% purity; white to brown; cub or hexagonal crystal(s); hex: a=0.4309nm, c=0.7021 nm, enthalpy of fusion 305.307 kJ/mol; becomes red in sunlight; used as a red pigment, in semiconductors, and as an evaporation material and sputtering target to produce photoconductive films and infrared filters; possible use in the electrofabrication of microdiode arrays [HAW93] [MER06] [CER91] [KLE93] [KRE91]

Physical properties

The energy gap of the hexagonal CdSe obtained from the absorption measurement Eg (Γ6–Γ1 ) is E_g=1.84 eV, temperature coefficient -4.6×10^-4 eV/K, and pressure coefficient 3.7×10^-6 eV/kg–cm ^-2 .
The band structure of cubic CdSe is similar to that of GaAs.

Uses

In photoconductors, semiconductors, photoelectric cells, and rectifiers; in phosphors.

Uses

Cadmium selenide is used as a n-type semiconductor and its nanoparticles are used in laser diodes, opto-electronic devices, nanosensing, biomedical imaging and high efficiency solar cells. Since, it is transparent to infrared light, it finds application in photoresistors and windows for instruments utilizing IR light.

Uses

Dispersions with CdS (Aldrich products 208183, 217921) deposited on glass or Si substrates results in tunable red, yellow, or green fluorescent material.

Definition

ChEBI: Cadmium selenide is a cadmium molecular entity.

Production Methods

A single crystal can be grown artificially through the vapor phase method or the Stockbarger method.
To obtain evaporated films, the source materials are heated in the alumina crucible with a nichrome heater. Crystal with a larger grain size is obtained at a higher substrate temperature.
The following corrosives are reported:
HNO3 (water cleansing after 2–3 s)
H2SO4 (water cleansing after 5–10 s)
18 N solution of 30 HNO3:0.1 HCl:20 H2SO4 (40℃, 8 s, cleansing with concentrated H2SO4)
3 HCl:1 HNO3

Application

Cadmium selenide is used as a photoconductive detector for λ: 0.3–0.72 mm (a sharp peak at 0.7 mm) at room temperature. The typical performances are as follows:
Peak detectivity: 2.1×10¹¹ cm Hz^1/2/watt, (λ: 0.7 mm)
Response time: ca. 12 ms
Intermittent frequency: 90 Hz
Dominant noise: current noise

General Description

CdSe crystal can exist in solid hexagonal or cubic structure. CdSe behaves as an n-type semiconductor, with a bandgap of 1.74 eV (300K).1

Flammability and Explosibility

Not classified

Structure and conformation

The space lattice of CdSe (Cadmium selenide) belongs to the two types of crystal system, the cubic system, with the zinc-blend type structure that has a lattice constant of a=0.605 nm, and the hexagonal system, with the wurtzite type structure that has lattice constants of a=0.430 nm and c=0.702 nm.