Durham E-Theses Semiconductors 1853-1919: an historical study of selenium and some related materials Hempstead, Colin Antony How to cite: Hempstead, Colin Antony (1977) Semiconductors 1853-1919: an historical study of selenium and some related materials, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/8205/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk 2 SEMIGOIDUCTORS 1853-1919: AF HISTORICAL STUDY OP SEIENIUM AND SOME RELATED MATERIALS. COLIN ANTONY HEMPSTEAD. DEGREE: DOCTOR OP PHILOSOPHY. INSTITUTION: UNIVERSITY OP DURHAM, DEPARTMENT: PHILOSOPHY. YEAR OP SUBMISSION: 1977. The copyright of this thesis rests with the author. No quotation from it should be published without his prior written consent and information derived from it should be acknowledged. No part of this thesis has- previously "been suhmitted for a degree in any Uniyersity. The copyright of this- thesis rests with the author. No quotation from it should he published without his prior written consent and information derived from it should be acknowledged. CONTENTS. ACKNOWLEDGEMENTS (i) ABSTRACT (ii) CHAPTER 1, Introduction and Outline of Research, 1. The Present Significance of Semiconductors 1 2. Historical Outline 6 3. Periods in the History of Semiconductors 16. 4. Historiography 18 CHAPTER 2. Semiconductors before the Electron 24 Theory, 1. The Work of Paraday 25 2. Photoconductivity, Rectification, 28 Photovoltaic Effects 3. The Discovery of Photoconductivity 30 4. Siemens' Theory 35 5. The Researches of Adams and Day 42 The Seat of Rectification in Selenium 63 and the Reality of Photoconductivity 1: The Researches of Shelford Bidwell 68 CHAPTER 3. Some Technological and Theoretical 96) Considerations to the End of the Nineteenth Century. 1. Technologjf 97 2'. Theory 110 3. Thomson's 'Recent Researches' 113 4. The Hall Effect 119 5. Bidwell and the Hall Effect 124 6. Electrical Theory in the late nineteenth 129 century 7. Lodge's Reviews' and Views 134 8. Problems with Electrolysis 141 9. Junction Phenomena 150 10. The Relation between Experimental 157 Discoveries and Theories CHAPTER 4, Experimental work to 1920, 163 1, Selenium - An overview 164 2. The Demise of Bidwell's Theory 166 3. The work of Brown - A Methodological View 176 4. Brown's Aliotropic Theory 180 5, Experimental Justification for the Allotrope 188 Theory 6, The Allotrope Theory - A Summary 194 7. Movement from tlie Allotrope Theory 196^ 8. Single Crystals 201 9. Brown's Use of Sources 209 10. Rectification) 215 11. Photoconductivity in Materials other 221 than Selenium 12. The Hall Effect 222 SUMARY 223 CHAPTER 5. The Theory of Electrons and 227 Semiconductors.' 1. Electron Theory - Sources 228 2. The Electron] Theory 230 3. Pfund's Electronic Theory of 238 Pho 10 c 0 nduc t ivi ty 4. Pirst Steps to an Electron Theory 240 5. Nicholson's Theory 245 6J. Brown's Electronic Theory of 251 Photoconductivity 7, The Class of Semiconductors 259 8. Effect of work on Semiconductors on 264 the Electron Theory CHAPTER 6. Recapitulations. Conclusions-, 270 Epilogue. 1. Recapitulations' and Conclusions 270 2. Epilogue 27'6 REFERENCES and NOTES. 287 Chapter 1 288 Chapter 2- 294 Chapter 3 311 Chapter 4 329 Chapter 5 346 Chapter 6 357 BIBLIOGRAPHY. 361 Puhlished Sources 361 Letters 386 Interviews 387 (i) ACKNOWLEDGEMENTS. My thanks are first offered to my Supervisor, Dr. David Knight of Durham, whose encouragement, help and gentlemanly pressure ensured the production of this thesis. Teesside Polytechnic offered me time and facilities in order that the path of my research should he as smooth as' possihle; and to the Librarians of that Institution I owe a particular deM of gratitude. Finally to my family my acknowledgement is extended; their encouragement was ever' present and their occasional help with some of the more tedious aspects of historical research and writing was always gratefully received. (ii) SEMICONDUCTORS 1833-1919; AN HISTORICAL STUDY OP SELjjiNlU^ and SOte RELATED MATERIALS. Abstract by C,A. Hempstead, (1977). The history of semiconductors began in 1833 when Paraday noted that the conductivity of s'ilver sulphide increased with temperature. This study ends in 1919 when Pohl went to GOttingen. Pive periods are identified: 1833-1895; ^ 1895-1919; 1919-1931; 1931-1948; 1948-present, Only towards the close of the second period was the semiconductor 'class' recognised; until then researches on selenium did not interact with those on other materials, Paraday's discovery excited little interest, but photoconductivity in selenium, 1873, engendered considerable activity during which rectification and photovoltaicity were noted, Allotropic and electrolytic theories were suggested, (by 1877), with the latter being extensively developed. Theories of electricity were insufficiently agreed to form other than a qualitative base for conduction in solids; until the electron theory and Arrhenius's picture, electrolysis was not an unsatisfactorj^ basis on which to construct an account of the properties of selenium, 4 The understanding of electrolysis and the electron theory made an alternative description of the action of selenium desirable and attractive. Initially, to cl912, an allotropic theory was developed to be replaced, by 1914, by an electron theory for there was no direct empirical evidence in support of the former. With the adoption of an electron theory selenium was no longer unique and its properties were compared with those of other non-metallic, non-electrolytic conductors, (cl915)« With the electron at the root of all electrical properties a new class of materials was defined, the halbleiter, but at the same time the shortcomings of the 'electron gas' theory were highlighted, By 1919 work on polycrystalline selenium and naturally occurring materials had extended electrical knowledge; but Pohl's work on single crystals and the development of the quantum theory paved the way for the modern understanding; an understanding whose theoretical beginning was Wilson's theory of 1931. - 1 - CHAPTER 1. Introduction and Outline of Research. 1. The Present Significance of Semiconductors. It is not inappropriate to hegin this historical study with a brief consideration of the present situation, although, as much work is being actively pursued, it is impossible to include more than a sketchy and more or less outdated picture of modern developments. The study of semiconductors forms part of the much wider field of the solid state where the study of crystalline materials has been enlarged to include investigations into the properties of glassy materials''' and began to become part of the 'establishment' of science in the 1950's. The interests of commercial concerns showed a similar pattern in the period^ with the spread of transistor technology and the establishment and enlargement of research and development laboratories.^ One major source of impetus to the development of effective semiconductor devices was the demands of the military, placing very difficult problems before engineers and scientists, particularly those working in the areas of guided weapons and space technology. The expenditure of government money greatly encouraged the development of solid state devices and led, eventually, to their spread into the civil field.^ (Investigations at present being undertaken by a group at the University of Aston may throw some light on the determinants of 1 I I • - 2 - innovation in the semiconductor industry. In particular they are examining the relationship between expectations and achievements in the s-emiconductor industry since the introduction of the transistor,^0 The particular problems of missile technology/, for example shortage of power, lack of space and the need for complex electronics for the purposes of information processing coupled with stringent requirements for robustness, were inadequately met bjy the miniaturised valves of the earl;y 1950's. These difficulties were dramatically^ eased by the introduction of the transistor, and particularly hyj the silicon transistor in the late 1950's. The advantages were so marked that, in the case of one British firm at least;, considerable trouble and expense was undertaken to ensure the supply^ of suitable devices for incorporation into their guided missile.'^ Under the aegis of government spending the transistor rapidly evolved from its original role as a single component, to be compared with a valve in the same situation, to just one member of a complete 'solid' circuit. New production techniques allowed and encouraged the introduction of integrated circuits with concomitant decreases in size and increases in reliabilityr. In recent years much has been written on the evolution of solid state technology; and the technology changes so rapidly that it is difficult to be completely up to date. Typical of many writings- - 3 - and opinions are the thoughts expressed, in a recent q article published in Scientific American^, in which the following passages appear. 'It: is now about 15 years since the electronics industry learned how to make miniature electronic circuits on a "chip" of silicon substrate by alternating processes of masked etching and diffusion.-'-'^ In the early 1960's the commercially available integrated circuits incorporated at most a score of components such as diodes, transistors and resistors. Production yields (the fraction of circuits that worked) were low, and packaging technology did not allow the realisation of practical devices with more than a dossen leads, or connections.