It was noted that the subject of point defects in semiconductors, especially Si, had gone through major evolutionary changes during the past 50 years and had reached a high level of maturity some 5 to 10 years ago. It was questioned whether there were any major new frontiers to address, or merely obstinate and persistent problems. The present review recalled some of the main historical highlights, considered some of the obstinate problems, mentioned some new advances, and outlined new avenues.

S.T.Pantelides: Solid State Phenomena, 1996, 47-48, 237-46