External Quantum Efficiency Calculator

External Quantum Efficiency Formula:

\[ \eta_{ext} = \frac{1}{4\pi} \int_{0}^{\theta_c} T_f[x] \cdot 2\pi \sin(x) dx \]

External Quantum Efficiency (η_ext):

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1. What is External Quantum Efficiency?

External Quantum Efficiency (EQE) is a measure used to quantify the efficiency of a photodetector or a semiconductor device in converting incident photons into electrical charge carriers. It represents the ratio of the number of charge carriers collected by the device to the number of photons incident on the device.

2. How Does the Calculator Work?

The calculator uses the External Quantum Efficiency formula:

\[ \eta_{ext} = \frac{1}{4\pi} \int_{0}^{\theta_c} T_f[x] \cdot 2\pi \sin(x) dx \]

Where:

\( \eta_{ext} \) — External Quantum Efficiency (dimensionless)
\( T_f[x] \) — Fresnel Transmissivity (dimensionless)
\( \theta_c \) — Cone of Acceptance Angle (radians)
\( \pi \) — Archimedes' constant (≈3.14159)
\( \sin(x) \) — Sine trigonometric function

Explanation: The formula integrates the product of Fresnel transmissivity and the angular distribution of incident light over the acceptance cone angle to determine the overall quantum efficiency.

3. Importance of EQE Calculation

Details: Accurate EQE calculation is crucial for evaluating the performance of photodetectors, solar cells, and other optoelectronic devices. It helps in optimizing device design and comparing different semiconductor materials.

4. Using the Calculator

Tips: Enter Fresnel Transmissivity (dimensionless value between 0-1) and Cone of Acceptance Angle in degrees. Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is the typical range for External Quantum Efficiency?
A: EQE typically ranges from 0 to 1 (0% to 100%), where 1 represents perfect conversion of photons to charge carriers.

Q2: How does Fresnel Transmissivity affect EQE?
A: Higher Fresnel transmissivity allows more light to enter the device, potentially increasing the external quantum efficiency.

Q3: What is the significance of the acceptance cone angle?
A: The acceptance cone angle defines the angular range within which the device can efficiently capture incident photons.

Q4: Are there limitations to this calculation?
A: This calculation assumes ideal conditions and may not account for all real-world factors like surface recombination, absorption losses, or angular dependence of transmissivity.

Q5: How can EQE be improved in practical devices?
A: EQE can be improved through anti-reflection coatings, better light trapping structures, optimized material selection, and reduced recombination losses.