Homework Help is Here – Start Your Trial Now!
Science
Chemistry
Semiconductor materials are the basis of modern electronics Conduction band (e.g. the transistors, memory and camera in your cell phones). Common semiconductor materials include Si, GaAs and CdSe. The energy states of semiconductors are generally divided into the valence band, where the electrons are bound to the atoms, 2S(e) 1D(e) and the conduction band where the wavefunction solutions of 1P(e) electrons allow some of them (the excited electrons) to move through the bulk material. The energy difference between the maximum energy level of the valence band, termed the valence band maximum (VBM), and the lowest energy of the conduction band, termed the conduction band minimum (CBM), of bulk CdSe is 1.74 eV. As shown in the figure, this difference is known as the bandgap energy, Eg. The CBM can be regarded as the excited state while the VBM can be regarded as the ground state. (we will not concern ourselves with the S, P, etc. orbital designations in the figure). 1S(e) Eg(QD) 1S(h) 1P(h) 2S(h) 1D(h) Valence band "Quantum dots" behave differently than extended semiconductors; in a CdSe quantum dot, electrons can be regarded as particles in a well, but for this question we will treat them as particles in a box. The mass of the electron is m1=0.13xmo in the CBM while it is m2=-0.45xmo in the VBM, where mo is the mass of the free electron, 9.109x10-31 kg.

Semiconductor materials are the basis of modern electronics Conduction band (e.g. the transistors, memory and camera in your cell phones). Common semiconductor materials include Si, GaAs and CdSe. The energy states of semiconductors are generally divided into the valence band, where the electrons are bound to the atoms, 2S(e) 1D(e) and the conduction band where the wavefunction solutions of 1P(e) electrons allow some of them (the excited electrons) to move through the bulk material. The energy difference between the maximum energy level of the valence band, termed the valence band maximum (VBM), and the lowest energy of the conduction band, termed the conduction band minimum (CBM), of bulk CdSe is 1.74 eV. As shown in the figure, this difference is known as the bandgap energy, Eg. The CBM can be regarded as the excited state while the VBM can be regarded as the ground state. (we will not concern ourselves with the S, P, etc. orbital designations in the figure). 1S(e) Eg(QD) 1S(h) 1P(h) 2S(h) 1D(h) Valence band "Quantum dots" behave differently than extended semiconductors; in a CdSe quantum dot, electrons can be regarded as particles in a well, but for this question we will treat them as particles in a box. The mass of the electron is m1=0.13xmo in the CBM while it is m2=-0.45xmo in the VBM, where mo is the mass of the free electron, 9.109x10-31 kg.

Chemistry
Chemistry
10th Edition
ISBN:9781305957404
Author:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Chapter1: Chemical Foundations
Section: Chapter Questions
Problem 1RQ: Define and explain the differences between the following terms. a. law and theory b. theory and...
See similar textbooks
icon
Related questions
Question
Semiconductor materials are the basis of modern electronics Conduction band (e.g. the transistors, memory and camera in your cell phones). Common semiconductor materials include Si, GaAs and CdSe. The energy states of semiconductors are generally divided into the valence band, where the electrons are bound to the atoms, 2S(e) 1D(e) and the conduction band where the wavefunction solutions of 1P(e) electrons allow some of them (the excited electrons) to move through the bulk material. The energy difference between the maximum energy level of the valence band, termed the valence band maximum (VBM), and the lowest energy of the conduction band, termed the conduction band minimum (CBM), of bulk CdSe is 1.74 eV. As shown in the figure, this difference is known as the bandgap energy, Eg. The CBM can be regarded as the excited state while the VBM can be regarded as the ground state. (we will not concern ourselves with the S, P, etc. orbital designations in the figure). 1S(e) Eg(QD) | 1S(h) 1P(h) 2S(h) 1D(h) Valence band "Quantum dots" behave differently than extended semiconductors; in a CdSe quantum dot, electrons can be regarded as particles in a well, but for this question we will treat them as particles in a box. The mass of the electron is m1=0.13×mo where mo is the mass of the free electron, the CBM while it is m2=-0.45xmo in the VBM, kg. 9.109x10-31
Transcribed Image Text:Semiconductor materials are the basis of modern electronics Conduction band (e.g. the transistors, memory and camera in your cell phones). Common semiconductor materials include Si, GaAs and CdSe. The energy states of semiconductors are generally divided into the valence band, where the electrons are bound to the atoms, 2S(e) 1D(e) and the conduction band where the wavefunction solutions of 1P(e) electrons allow some of them (the excited electrons) to move through the bulk material. The energy difference between the maximum energy level of the valence band, termed the valence band maximum (VBM), and the lowest energy of the conduction band, termed the conduction band minimum (CBM), of bulk CdSe is 1.74 eV. As shown in the figure, this difference is known as the bandgap energy, Eg. The CBM can be regarded as the excited state while the VBM can be regarded as the ground state. (we will not concern ourselves with the S, P, etc. orbital designations in the figure). 1S(e) Eg(QD) | 1S(h) 1P(h) 2S(h) 1D(h) Valence band "Quantum dots" behave differently than extended semiconductors; in a CdSe quantum dot, electrons can be regarded as particles in a well, but for this question we will treat them as particles in a box. The mass of the electron is m1=0.13×mo where mo is the mass of the free electron, the CBM while it is m2=-0.45xmo in the VBM, kg. 9.109x10-31
(a) A photon is generated when an electron jumps from the CBM to the VBM in semiconductors in (bulk) CdSe. What is the wavelength of the associated photon that is emitted? What is its color? (b) Suppose we synthesize a CdSe quantum dot with size 3.0 nm diameter. Calculate the ground state energies assuming a particle in a box model for the energy states of the CBM and the VBM, respectively. (c) In the case described in part (b), if an electron transfers from the CBM to the VBM, what is the wavelength of the light generated by the process? (d) If the size of the quantum dot synthesized in part (b) is 2.0 nm, repeat the calculations in (b) and (c): calculate the ground state energies of particle in a box model at the CBM and the VBM, respectively and compute the wavelength of the light generated by an electron transferring from the CBM to the VBM.
Transcribed Image Text:(a) A photon is generated when an electron jumps from the CBM to the VBM in semiconductors in (bulk) CdSe. What is the wavelength of the associated photon that is emitted? What is its color? (b) Suppose we synthesize a CdSe quantum dot with size 3.0 nm diameter. Calculate the ground state energies assuming a particle in a box model for the energy states of the CBM and the VBM, respectively. (c) In the case described in part (b), if an electron transfers from the CBM to the VBM, what is the wavelength of the light generated by the process? (d) If the size of the quantum dot synthesized in part (b) is 2.0 nm, repeat the calculations in (b) and (c): calculate the ground state energies of particle in a box model at the CBM and the VBM, respectively and compute the wavelength of the light generated by an electron transferring from the CBM to the VBM.
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 2 steps with 2 images

SEE SOLUTIONCheck out a sample Q&A here
Blurred answer
Knowledge Booster
Applications of MOT and Spectroscopy to Symmetry
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.
Similar questions
Recommended textbooks for you
Chemistry
Chemistry
Chemistry
ISBN:
9781305957404
Author:
Steven S. Zumdahl, Susan A. Zumdahl, Donald J. DeCoste
Publisher:
Cengage Learning
Chemistry
Chemistry
Chemistry
ISBN:
9781259911156
Author:
Raymond Chang Dr., Jason Overby Professor
Publisher:
McGraw-Hill Education
Principles of Instrumental Analysis
Principles of Instrumental Analysis
Chemistry
ISBN:
9781305577213
Author:
Douglas A. Skoog, F. James Holler, Stanley R. Crouch
Publisher:
Cengage Learning
Organic Chemistry
Organic Chemistry
Chemistry
ISBN:
9780078021558
Author:
Janice Gorzynski Smith Dr.
Publisher:
McGraw-Hill Education
Chemistry: Principles and Reactions
Chemistry: Principles and Reactions
Chemistry
ISBN:
9781305079373
Author:
William L. Masterton, Cecile N. Hurley
Publisher:
Cengage Learning
Elementary Principles of Chemical Processes, Bind…
Elementary Principles of Chemical Processes, Bind…
Chemistry
ISBN:
9781118431221
Author:
Richard M. Felder, Ronald W. Rousseau, Lisa G. Bullard
Publisher:
WILEY
SEE MORE TEXTBOOKS