The Photoelectric Effect – Experimental Confirmation Concerning a Widespread Misconception in the Theory
Title
The Photoelectric Effect – Experimental confirmation concerning a widespread Misconception in the Theory
Gao Shenghan 1, Huan Yan Qi 1, Wang Xuezhou 1, Darren Wong 2, Paul Lee 2 and Foong See Kit 2
1 Raffles Institution, One Raffles Institution Lane, Singapore 575954
2 Natural Sciences and Science Education, National Institute of Education,
Nanyang Technological University, Singapore 637616
Abstract
The photoelectric effect is a well-known and widely taught field in many schools and institutions, yet it has been shown through theoretical arguments that there is a common error in the theory in which this topic is learnt and taught. The common theory is that the energy of the incoming photons must be greater than the work function of the emitter, and also that the difference between the energy of the photon and the work function of the emitter must be greater than the voltage applied between the emitter and collector multiplied by the elementary charge. This paper provides experimental evidence for the correct interpretation of the photoelectric effect in order to correct the misconception. In this paper, it was experimentally determined that both the work functions of the emitter and the collector metals must be taken into account in order for a current to be detected, contrary to conventional theory.
Introduction
The photoelectric effect is the phenomenon in which electrons are liberated from matter as a result of electromagnetic radiation being shone onto it. Generally, the phenomenon is only investigated in metals as they require lower energy from the radiation.
The photoelectric effect was first discovered by Heinrich Hertz in 1887 and was explained by Albert Einstein in 1905.
Einstein’s model quantized light as photons, each with energy E=hν where h is the Planck’s constant and ν is the frequency. Einstein also introduced the work function ϕ of a material, defined as the minimum amount of energy needed in order to liberate an electron
The Photoelectric Effect – Experimental confirmation concerning a widespread Misconception in the Theory
Gao Shenghan 1, Huan Yan Qi 1, Wang Xuezhou 1, Darren Wong 2, Paul Lee 2 and Foong See Kit 2
1 Raffles Institution, One Raffles Institution Lane, Singapore 575954
2 Natural Sciences and Science Education, National Institute of Education,
Nanyang Technological University, Singapore 637616
Abstract
The photoelectric effect is a well-known and widely taught field in many schools and institutions, yet it has been shown through theoretical arguments that there is a common error in the theory in which this topic is learnt and taught. The common theory is that the energy of the incoming photons must be greater than the work function of the emitter, and also that the difference between the energy of the photon and the work function of the emitter must be greater than the voltage applied between the emitter and collector multiplied by the elementary charge. This paper provides experimental evidence for the correct interpretation of the photoelectric effect in order to correct the misconception. In this paper, it was experimentally determined that both the work functions of the emitter and the collector metals must be taken into account in order for a current to be detected, contrary to conventional theory.
Introduction
The photoelectric effect is the phenomenon in which electrons are liberated from matter as a result of electromagnetic radiation being shone onto it. Generally, the phenomenon is only investigated in metals as they require lower energy from the radiation.
The photoelectric effect was first discovered by Heinrich Hertz in 1887 and was explained by Albert Einstein in 1905.
Einstein’s model quantized light as photons, each with energy E=hν where h is the Planck’s constant and ν is the frequency. Einstein also introduced the work function ϕ of a material, defined as the minimum amount of energy needed in order to liberate an electron
References: [1] Young, H. D., Freedman, R. A., & Ford, A. L. (2008). Sears and Zemansky 's University Physics 12th edition with modern physics. San Fransisco, California, United States of America: Pearson Addison-Wesley. [2] Einstein, A. (1905). Über einen die Erzeugung und Verwandlung des Lichtes betreffenden heuristischen Gesichtspunkt. Annalen der Physik, 17, 132–148. [3] Nobelprize.org. (2010, July 12). The Nobel Prize in Physics 1921. Retrieved from http://nobelprize.org/nobel_prizes/physics/laureates/1921/index.html [4] James, A. N. (1973). Photoelectric effect, a common fundamental error. Physics Education, 8(6), Retrieved from http://iopscience.iop.org/0031-9120/8/6/005 doi: 10.1088/0031-9120/8/6/005 [5] Rudnick, J., & Tannhauser, D. S. (1976). Concerning a widespread error in the description of the photoelectric effect. American Journal of Physics, 44(8), 796-798. [6] Barbalace, K. (2007, February 22). Environmentalchemistry.com. Periodic table of elements: Nickel (Ni). Retrieved from http://environmentalchemistry.com/yogi/periodic/Ni.html