{{short description|German solid state physicist (1931–2025)}} {{Use dmy dates|date=July 2025}} {{Infobox scientist | name = Hans-Joachim Queisser | honorific_prefix = | image = Hans-JoachimQueisser1995.jpg | image_upright = 0.9 | caption = Queisser in 1995 | birth_date = {{birth date|1931|07|06|df=y}} | birth_place = Berlin, Brandenburg, Prussia, Germany | death_date = {{death date_and_age|2025|6|27|1931|07|06|df=y}} | death_place = | education = University of Berlin<br>University of Kansas<br>University of Göttingen | doctoral_advisor = Rudolf Hilsch | academic_advisors = | workplaces = Shockley Transistor Corporation<br>University of Frankfurt<br>Max Planck Institute for Solid State Research | doctoral_students = Horst Ludwig Störmer<br>Karl Leo | known_for = Shockley–Queisser limit | website = }}
'''Hans-Joachim Queisser''' (6 July 1931 – 27 June 2025) was a German solid-state physicist. He was best known for co-authoring the 1961 work on solar cells that detailed what is today known as the Shockley–Queisser limit, now considered the key contribution in this field.<ref name=history>{{cite web |url= http://www.computerhistory.org/events/bio/Hans,Queisser |title= Hans Queisser |publisher= Computer History Museum |accessdate = 17 January 2017}}</ref>
== Education and career == Queisser was born in Berlin and his father was a mechanical engineer for Siemens. In 1928, he travelled to the United States to work on power plants and asked his fiancée to join him. She wanted to return to Germany, and Hans Joachim was born shortly after their return in 1931, in Berlin. He was in Dresden during the air raid in 1945 and states that he survived "barely".<ref name=addison>Craig Addison, [http://archive.computerhistory.org/resources/text/Oral_History/Queisser_Hans/Queisser_Hans_1.oral_history.2006.102658051.pdf "Oral History of Han Queisser"], Computer History Museum, 27 February 2006.</ref> His father was sent to the Soviet Union after the war, and Queisser wanted to enter the University of Berlin through an apprenticeship program and work as a technician at a research institute in Berlin. However, he instead applied for a scholarship in the United States and was accepted to the University of Kansas in 1951 and 1952. He returned to Germany and obtained his Ph.D. in physics at the University of Göttingen in 1958 under the supervision of Rudolf Hilsch.<ref name=addison/>
After graduating in Göttingen, Queisser accepted a job at the Shockley Transistor Corporation in Mountain View, California, where he worked on crystal growth, epitaxy, diffusion, lattice defects, junction properties and solar cells. During this time, he and Shockley calculated the maximal theoretical efficiency of silicon solar cells to be around 31%.<ref> William Shockley and Hans J. Queisser, "Detailed Balance Limit of Efficiency of ''p''-''n'' Junction Solar Cells", ''Journal of Applied Physics'', Volume 32 (March 1961), pp. 510–519; {{doi|10.1063/1.1736034}}.</ref> He and his co-worker Richard Finch identified oxygen-induced stacking faults and achieved the first transmission electron microscopy on semiconductors with J. Washburn and G. Thomas at UC Berkeley.<ref name=history/>
Queisser left Shockley for Bell Labs in 1964, working on gallium arsenide for optoelectronics. During this time, he invented a high-power luminescent diode, an infrared light emitting diode (LED) that now forms the basis of almost every household remote control device.<ref name=history/> Modifications of the basic design represent practically every LED in existence today. In 1966, he left Bell to become a professor at the University of Frankfurt. In 1970, he became a founding director of the Max Planck Institute for Solid State Research at Stuttgart. He served in this role until his retirement in 1998.
== Death == Queisser died on 27 June 2025, at the age of 93.<ref>[https://www.fkf.mpg.de/8745141/2025_07_Queisser "In memory of Prof. Dr. Hans-Joachim Queisser"]. fkf.mpg.de, 2 July 2025 (text in German). Retrieved 3 July 2025.</ref>
== Honours and awards == Queisser became a member of the German Academy of Sciences Leopoldina in 1994.<ref>{{cite web |title= Hans-Joachim Queisser |url=https://www.leopoldina.org/mitgliederverzeichnis/mitglieder/member/Member/show/hans-joachim-queisser/|publisher=German Academy of Sciences Leopoldina |access-date=1 June 2021}}</ref> He was a Fellow of the American Physical Society. He was president of the German Physical Society between 1976 and 1977.<ref>{{Cite web |title=Hans Queisser |url=https://computerhistory.org/profile/hans-queisser/ |access-date=6 January 2023 |website=CHM |language=en}}</ref>
==References== {{Reflist}}
==External links== * [https://www.amazon.com/Conquest-Microchip-Hans-Queisser/dp/0674162978 "The Conquest of the Microchip"], Queisser's autobiographical work on the early history of Silicon Valley, {{ISBN|0-674-16297-8}} * [http://www.semizone.com/webcast/product?usca%5fp=t&product%5fid=301&corporate%5fp=0&partner%5fid=0&info%5fp=0 "Bringing Silicon to the Valley"], presentation by Queisser on the history of Silicon Valley, with materials.
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{{DEFAULTSORT:Queisser, Hans}} Category:1931 births Category:2025 deaths Category:20th-century German physicists Category:Officers Crosses of the Order of Merit of the Federal Republic of Germany Category:Recipients of the Order of Merit of Baden-Württemberg Category:Fellows of the American Physical Society Category:Members of the German National Academy of Sciences Leopoldina Category:Presidents of the German Physical Society Category:Max Planck Institute directors Category:Academic staff of Goethe University Frankfurt Category:Humboldt University of Berlin alumni Category:University of Göttingen alumni Category:Scientists from Berlin