It is common that the p-type wide-gap semiconductors are difficult to obtain

however

it is fortunate to observe that the delafossite structured ABO

2

(

A

=Cu or Ag;

B

=Al

Cr

or La) compounds are p-type wide-gap semiconductors with high optical transparency

and the gap is higher than 3.1 eV for these mate-rials. The ABO

2

compounds also show rather large power factor compared to other oxide materials. Therefore

it is expected to apply these materials in transparent semiconducting devices as well as in thermoelectric applications.The delafossite structured single phase CuBO

2

(

B

=Al

Cr

La)ceramics were synthesized by sol-gel and high temperature solid state reaction

respectively. Moreover

CuCrO

2

films were prepared by pulsed laser deposition (PLD) using the synthesized single phase CuCrO

2

ceramics as targets. The crystallization and microstructure of the samples were investigated by X-ray diffractometer (XRD) and field-emission scanning electron microscope (FE-SEM). The electron dispersion spectrum (EDS) was also used to determine the chemical composition. The temperature dependence of conductivity was measured by the standard two-probe method. Optical transmission spectra of the films were measured by a dual beam spectrophotometer. The study results showed that sol-gel was an effective approach to synthesize single phase CuAlO

2

and CuCrO

2

ceramics

with shorter sintering period and lower annealing temperature. The temperature dependence of conductivity for CuAlO

2

and CuCrO

2

ceramics showed that these two materials behaved as semiconductors around room temperature. Additionally

the room temperature conductivity of CuBO

2

(

B

=Al

Cr

La) decreased obviously with the increase of the radius of ions on B site. CuCrO

2

thin films with high c-axis orientation were successfully prepared by PLD

and the optical transmittance of the CuCrO

2

film with the thickness ~200 nm was about 80% in the visible region.