Thursday, August 24, 2006

US Patent 7094617 - Optoelectronic Nanodot Manufacture

http://www.freepatentsonline.com/7094617.pdf

This patent involves the manufacture of nanodots for light sensors or radiation devices. It teaches the formation of a dual layer hole-injection/electron-injection structure for the nanodot. Claim 1 reads:

1. A method of manufacturing an optoelectric device, comprising the steps of: forming an electron injection layer on a semiconductor substrate; growing nano dot layer on said electron injection layer by an epigrowth method; heating said nano dot layer so that said nano dot has a dual structure comprising an external nano dot and an internal nano dot; and forming a hole injection layer on the overall structure.

The interesting thing about this patent is that it has the cleanest prosecution history I've ever seen. The application was allowed by the Examiner on a first action (most patent applications initially have at least one claim rejected). The Examiners reasons for allowance read:

"The following is the examiner's statement of reasons for allowance: See claim 1 and the prior art search history for claim 1."

Unfortunately there is very little indication of non-patent literature searching except for IBM_TPB which is a very limited source. What is worse is that the Examiner limited the search for terms including nano adjacent to dot excluding patent references using nanodot (one word) or quantum dot or nanocrystal or nanoparticle, etc. to describe the invention.