Bernhard Gross and electret research: his contributions, our collaboration, and what followed

Bernhard Gross has inspired and stimulated electret research over the past 70 years. The following article will be a tribute to his contributions to this field. In the first part, some of the seminal early work of Gross will be discussed. This is followed by reminiscences of the author to joint work on radiation charging, carrier transport, and other aspects of electrets at Bell Laboratories and at the Darmstadt University of Technology. In the last part, recent work in Darmstadt on charge storage, charge transport, and piezoelectricity, still in part stimulated and accompanied by Bernhard Gross, will be discussed.