Decrease in work function of boron ion-implanted ZnO thin films.
We have fabricated boron ion-implanted ZnO thin films by ion implantation into sputtered ZnO thin films on a glass substrate. An investigation of the effects of ion doses and activation time on the electrical and optical properties of the films has been made. The electrical sheet resistance and resistivity of the implanted films are observed to increase with increasing rapid thermal annealing (RTA) time, while decreasing as the ion dose increases. Without any RTA process, the variation of the carrier density is insensitive to the ion dose. With the RTA process, however, the carrier density of the implanted films increases and approaches that of the un-implanted ZnO film as the ion dose increases. On the other hand, the carrier mobility is shown to decrease with increasing ion doses when no RTA process is applied. With the RTA process, however, there is almost no change in the mobility. We have achieved the optical transmittance as high as 87% within the visible wavelength range up to 800 nm. It is also demonstrated that the work function can be engineered by changing the ion dose during the ion implantation process. We have found that the work function decreases as the ion dose increases.
Heo
Gi-Seok
GS
Energy and Applied Optics Team, Gwangju Research Center, Korea Institute of Industrial Technology, Gwangju 500-480, Korea.
Hong
Sang-Jin
SJ
Park
Jong-Woon
JW
Choi
Bum-Ho
BH
Lee
Jong-Ho
JH
Shin
Dong-Chan
DC
D001895:Boron; D003460:Crystallization / Q000379:methods*; D004553:Electric Conductivity; D004735:Energy Transfer / Q000528:radiation effects; D020450:Heavy Ions; D008422:Materials Testing; D008567:Membranes, Artificial; D049329:Nanostructures / Q000737:chemistry* / Q000528:radiation effects*; D036103:Nanotechnology / Q000379:methods; D010316:Particle Size; D011829:Radiation Dosage; D013499:Surface Properties / Q000528:radiation effects; D015034:Zinc Oxide / Q000737:chemistry* / Q000528:radiation effects
D008567:Membranes, Artificial; D001895:Boron; D015034:Zinc Oxide