What is the band gap of ZnO?

What is the band gap of ZnO?

3.37 eV
ZnO has a band gap of 3.37 eV, which corresponds to emission in the UV region. This band gap is very close to that of GaN (3.39eV), and GaN has been the subject of much research over the past years, even being incorporated into the recent Blu-Ray drives.

Is ZnO a direct band gap?

Zinc oxide, an important semiconductor with a direct wide band gap and large exciton binding energy, has been used for solar cells, transparent electrodes, and blue/ultraviolet light emitting devices.

What is the band gap of ZnO nanoparticles?

The optical band gap value obtained for ZnO nanoparticle at pH=7.5 is 3.63 eV.

Is ZnO conductive?

Zinc oxide (ZnO) belongs to the class of transparent conducting oxides which can be used as transparent electrodes in electronic devices or heated windows.

What is semiconductor band gap?

The band gap of a semiconductor is the minimum energy required to excite an electron that is stuck in its bound state into a free state where it can participate in conduction. The band gap (EG) is the gap in energy between the bound state and the free state, between the valence band and conduction band.

Is ZnO a semiconductor?

ZnO is an n-type semiconductor with a bandgap of 3.3 eV, electron mobility about 10−4 to 10−3 cm2 V−1 S−1 and has been used as ETL in OPV since 1999. ZnO layers can be deposited either from sol–gel or from nanoparticular solutions.

What is ZnO used for?

Zinc oxide is an inorganic compound used in a number of manufacturing processes. It can be found in rubbers, plastics, ceramics, glass, cement, lubricants, paints, ointments, adhesives, sealants, pigments, foods, batteries, ferrites, fire retardants, and first-aid tapes.

What is band gap in conductors?

A band gap is the distance between the valence band of electrons and the conduction band. Essentially, the band gap represents the minimum energy that is required to excite an electron up to a state in the conduction band where it can participate in conduction.

Is ZnO conductor or insulator?

For the piezoelectric applications ZnO is considered as insulator; its relative dielectric permittivity is eps33=9.03. But in photovoltaic applications it is considered a semiconductor with Eg=3.4 EV.

What is band gap photocatalyst?

Composite photocatalyst. Composite photocatalysts are produced when the big band gap and energy of irradiated light is not enough to irradiate the semiconductor photocatalyst. The other semiconductor with small band gap are coupled to increase the efficiency under near UV or visible and solar light.

Does LDA+uaffect the valence and conduction bands of ZnO?

Uto Zn s states will also affect the position of theV Orelated state in a way that is, in our opinion, unphysical. Janottiet alobserved that LDA+Uaffects both valence and conduction bands of ZnO [165], and that the single- particle defect states are corrected according to their valence- versus conduction-band character.

What is the orbital theory of ZnO?

+ Oin n-type ZnO. (Based on [20]. With permission.) orbital theory that involves the four Zn dangling bonds (sp3hybrids) and two electrons. These Zn dangling bonds combine into a fully symmetric a 1state located in the band gap and three almost degenerate states in the conduction band.

What is the band gap of doped ZnO?

For the Mn-doped ZnO, the band gap widening is mainly due to the larger upward shift of the conduction band (Fig. 23). Band gap narrowing of doped compounds with respect to pure ZnO can be said to be mainly due to the downward shifts of the conduction band (Fig. 18) for both the nanostructured and micron materials.

What is the source of conductivity of ZnO?

sourceof conductivity. In ZnO, however, interstitial hydrogen occurs exclusively in the positive charge state, i.e. it always acts as a donor. Interstitial hydrogen in ZnO can be located at the bond- center (BC) site, or at the antibonding (AB