It is possible to convert radiant energy into electrical energy using photovoltaic cells. Assuming equal efficiency of conversion, would infrared or ultraviolet radiation yield more electrical energy on a per-photon basis?

Verified step by step guidance

1. Understand that the energy of a photon is given by the equation: $E = h \nu = \frac{hc}{\lambda}$, where $E$ is the energy, $h$ is Planck's constant, $\nu$ is the frequency, $c$ is the speed of light, and $\lambda$ is the wavelength.
2. Recognize that ultraviolet (UV) radiation has a shorter wavelength than infrared (IR) radiation. This means that for UV radiation, $\lambda$ is smaller compared to IR radiation.
3. Since the energy of a photon is inversely proportional to its wavelength ($E \propto \frac{1}{\lambda}$), photons with shorter wavelengths (like UV) have higher energy than those with longer wavelengths (like IR).
4. Conclude that on a per-photon basis, ultraviolet radiation would yield more electrical energy than infrared radiation, assuming equal efficiency of conversion.
5. Consider the practical implications: while UV photons have more energy, the efficiency of photovoltaic cells can vary based on the material and design, which might affect the overall energy conversion.

Key Concepts

Photon Energy

The energy of a photon is directly related to its frequency and inversely related to its wavelength, as described by the equation E = hν, where E is energy, h is Planck's constant, and ν is frequency. Higher frequency radiation, such as ultraviolet (UV), has more energy per photon compared to lower frequency radiation, like infrared (IR). This fundamental principle is crucial for understanding how different types of radiation can be converted into electrical energy.

Photovoltaic Effect

The photovoltaic effect is the process by which certain materials convert light energy into electrical energy. When photons strike a photovoltaic cell, they can excite electrons, creating electron-hole pairs that generate a flow of electricity. The efficiency of this conversion depends on the energy of the incoming photons, making it essential to consider the type of radiation when evaluating energy output.

Energy Conversion Efficiency

Energy conversion efficiency refers to the ratio of useful electrical energy output to the total energy input from radiation. In the context of photovoltaic cells, this efficiency can vary based on the wavelength of the incoming light. Since UV photons carry more energy than IR photons, assuming equal conversion efficiency, UV radiation would yield more electrical energy per photon than IR radiation, highlighting the importance of wavelength in energy conversion.