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nnp:optics:internal_quantum_efficiency
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nnp:optics:internal_quantum_efficiency [2017/02/02 17:32] stefan.birner [Physics Model] |
nnp:optics:internal_quantum_efficiency [2017/02/03 10:19] (current) stefan.birner [Recombination] |
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| ====== Emission: Internal Quantum Efficiency ====== | ====== Emission: Internal Quantum Efficiency ====== | ||
| - | In this tutorial we demonstrate how to calculate the internal quantum efficiency of a multi-quantum well structure as the function of the applied forward bias. | + | In this tutorial we demonstrate how to calculate the internal quantum efficiency of a multi-quantum well structure as a function of the applied forward bias. |
| ==== Physics Model ==== | ==== Physics Model ==== | ||
| **nextnano++** is capable of simulating recombination processes such as //Shockley-Read-Hall (SRH)//, //Auger// and //radiative// recombination. | **nextnano++** is capable of simulating recombination processes such as //Shockley-Read-Hall (SRH)//, //Auger// and //radiative// recombination. | ||
| - | Only the radiative //(direct)// recombination process generates photons (spontaneous emission). | + | Only the radiative //(direct)// recombination process (spontaneous emission) generates photons. |
| - | If it is summed up over the full device, it equals the total number of photons emitted from the device per second, the photocurrent: $I_{\rm photon}$. | + | If radiative recombination $R_{\rm sp}(x)$ is summed up over the full device, it equals the total number of photons emitted from the device per second, the photocurrent: $I_{\rm photon}$. |
| ;#; | ;#; | ||
| Line 20: | Line 20: | ||
| - | If the injected charge carrier current is $I_{charge}$, than the internal quantum efficiency is | + | If the injected charge carrier current is $I_{\rm charge}$, then the internal quantum efficiency $\eta_{\rm qe}$ is |
| ;#; | ;#; | ||
| - | $$\eta_{qe} = \frac{I_{photon}}{I_{charge}}$$ | + | $$\eta_{\rm qe} = \frac{I_{\rm photon}}{I_{\rm charge}}$$ |
| ;#; | ;#; | ||
| Line 36: | Line 36: | ||
| </Code> | </Code> | ||
| - | The internal quantum efficiency is automatically calculated when the radiative recombination is switched on | + | The internal quantum efficiency is calculated automatically when the radiative recombination is switched on |
| <Code> | <Code> | ||
| radiative = yes # radiative recombination (direct recombination) | radiative = yes # radiative recombination (direct recombination) | ||
| Line 44: | Line 44: | ||
| ==== Bandstructure ==== | ==== Bandstructure ==== | ||
| - | The band structure of the **MQW** structure can be seen of figure {{ref>bandstructure}} without bias voltage. | + | The band structure of the **MQW** structure can be seen in figure {{ref>bandstructure}} without bias voltage. |
| <figure bandstructure> | <figure bandstructure> | ||
| ;#; | ;#; | ||
| - | <dataplot center linepoints xrange=-100.0:180.0 yrange=-3.0:2.0 xlabel="x(nm)" ylabel="E(eV)" ylegends="Gamma LH HH SO Fermi_{electron} Fermi_{hole}" legendpos="right bottom" 600x400> | + | <dataplot center linepoints xrange=-100.0:180.0 yrange=-3.0:2.0 xlabel="Position (nm)" ylabel="Energy (eV)" ylegends="Gamma LH HH SO Fermi_{electron} Fermi_{hole}" legendpos="right bottom" 600x400> |
| -121 -0 -0 -0 -0 0 0 | -121 -0 -0 -0 -0 0 0 | ||
| -120.001 -0 -0 -0 -0 0 0 | -120.001 -0 -0 -0 -0 0 0 | ||
| Line 3480: | Line 3480: | ||
| </dataplot> | </dataplot> | ||
| ;#; | ;#; | ||
| - | <caption>Bandstructure with zero bias. Two Quantum wells with alloy structures //In(0.7)Ga(0.3)As//, and well barriers //In(0.53)Ga(0.47)As// </caption> | + | <caption>Band structure at zero bias. The two quantum wells consist of ${\rm In}_{0.7}{\rm Ga}_{0.3}{\rm As}$ and are surrounded by ${\rm In}_{0.53}{\rm Ga}_{0.47}{\rm As}$ barriers.</caption> |
| </figure> | </figure> | ||
| Line 3489: | Line 3489: | ||
| <figure recombination> | <figure recombination> | ||
| ;#; | ;#; | ||
| - | <dataplot center linepoints xrange=-50.0:150.0 xlabel="x(nm)" ylabel="I(1/cm^3/s)" ylegends="total SRH Auger radiative" legendpos="right top" 600x400> | + | <dataplot center linepoints xrange=-50.0:150.0 xlabel="Position (nm)" ylabel="R (1/cm^3/s)" ylegends="total SRH Auger radiative" legendpos="right top" 600x400> |
| -121 0 0 0 0 | -121 0 0 0 0 | ||
| -120 1249.9986884573 1249.9986884573 0 0 | -120 1249.9986884573 1249.9986884573 0 0 | ||
| Line 5209: | Line 5209: | ||
| </dataplot> | </dataplot> | ||
| ;#; | ;#; | ||
| - | <caption>Comparison of different recombination processes</caption> | + | <caption>Comparison of different recombination processes. The applied bias is 1 V.</caption> |
| </figure> | </figure> | ||
| - | ==== UI Characteristics==== | + | ==== Current-Voltage Characteristics==== |
| - | The $I-U$ characteristics of the device is plotted in figure {{ref>IUchar}}, where additionally the full photo-current is plotted. | + | The $I-V$ characteristics of the device is plotted in figure {{ref>IUchar}}. |
| + | This figure also includes the full photo current. | ||
| <figure IUchar> | <figure IUchar> | ||
| ;#; | ;#; | ||
| - | <dataplot center linepoints xlabel="U_{bias}(V)" ylabel="I(A/cm^2)" ylegends="I_{Right} I_{Left} I_{photo}" legendpos="left top" 600x400> | + | <dataplot center linepoints xlabel="Voltage (V)" ylabel="Current density (A/cm^2)" ylegends="I_{right} I_{left} I_{photo}" legendpos="left top" 600x400> |
| 0 0.0048007999 -0.004800798 8.5567076e-05 | 0 0.0048007999 -0.004800798 8.5567076e-05 | ||
| 0.1 7.8561578 -7.8561504 8.9688789e-05 | 0.1 7.8561578 -7.8561504 8.9688789e-05 | ||
| Line 5235: | Line 5236: | ||
| </dataplot> | </dataplot> | ||
| ;#; | ;#; | ||
| - | <caption>$I-U$ characteristic of the device with additional photo-current. The device had just two contacts which means the charge carrier currents on the left and the right contacts are equal in absolute value.</caption> | + | <caption>$I-V$ characteristics of the device and photo current. The device has two contacts and the charge carrier current densities at the left and at the right contact are equal in absolute value.</caption> |
| </figure> | </figure> | ||
| Line 5245: | Line 5246: | ||
| ;#; | ;#; | ||
| - | <dataplot center linepoints yrange=-0.005:0.8 xlabel="U_{bias}(V)" ylabel="IQE(-)" ylegends="" 600x400> | + | <dataplot center linepoints yrange=-0.005:0.8 xlabel="Voltage (V)" ylabel="IQE" ylegends="" 600x400> |
| 0 0.017823508 | 0 0.017823508 | ||
| 0.1 1.1416374e-05 | 0.1 1.1416374e-05 | ||
| Line 5261: | Line 5262: | ||
| </dataplot> | </dataplot> | ||
| ;#; | ;#; | ||
| - | <caption>Internal quantum efficiency in the function of the forward bias voltage</caption> | + | <caption>Internal quantum efficiency as a function of the forward bias voltage</caption> |
| </figure> | </figure> | ||
nnp/optics/internal_quantum_efficiency.1486056752.txt.gz · Last modified: 2017/02/02 17:32 (external edit)
