VISIBLE-LIGHT EMISSION FROM THE POROUS ALLOYED PT SI CONTACTS/

One of the major problems hindering the application of porous Si to el ectroluminescent devices is the high resistance of the electrode/porou s Si contact. To overcome the problem, we anodized the alloyed Pt/Si c ontacts to form porous alloyed Pt/Si contacts and studied the chemical compositions and photoluminescence (PL). The porous alloyed Pt/Si con tact exposed to the 488 nm line of the Ar ion laser light exhibits red -light emission (600-800 nm). The composition of the contact strongly depends on the alloying temperature, The PL spectra are similar to tha t of porous Si without Pt, and the peak wavelength is affected by the annealing process. However, the PL intensity is lower than that of por ous Si without Pt. This is either due to the subsurface layer with the Pt,Si phase keeping the Si layer underneath From being anodized or ke eping the emitted light from coming out of the surface. The I-V charac teristic of the porous alloyed Pt/Si contact demonstrates a good ohmic contact with a low contact resistance.