Enhanced field emission from polysilicon emitters using porous silicon

It is now well known that the field emission performance of single crystal silicon field emitters is improved by the formation of porous silicon on their surface. However, single crystal based displays are likely to be expensive and difficult to scale up. Displays based on polysilicon would have advantages in both of these respects. We now report the first observation of enhanced field emission from porous silicon on polysilicon emitters. Both wet and dry etching processes were used to produce emitters on n and p type polysilicon. Porous silicon was then formed by anodisation. Field emission characterisation after the anodisation shows a significant starting voltage reduction of 40-50% in each of the samples tested