The AM1.5G Spectrum - Standard Solar Spctrum

The solar spectrum changes throughout the day and with location. This is because of a combination of local atmospheric conditions and geometric considerations. The tropics, for example, receive more irradiance on average than the equator due to a lower prevalence of clouds, which reflect much of the incoming solar radiation (see Figure 1). This ...

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Open-circuit potential and photovoltage in photoelectrodes

The open-circuit potential (OCP, $V_\mathrm{oc}$) is the potential of the working electrode (WE) relative to the reference electrode (RE) under open-circuit condition (no potential or current is being applied to the cell). It can be established by leaving the potential of the WE uncontrolled, allowing it to achieve equilibrium with the electroly...

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Metrics for evaluating PEC performance

By definition, the efficiency for any process that converts energy from one form to another is the ratio of the total power output to the total power input. For PEC systems, the solar-to-hydrogen (STH) efficiency is the single value by which all PEC devices can be reliably ranked against one another, which can be directly determined by analysis ...

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Calculation of the theoretical maximum photocurrent

 Let us assume that we have an ideal photoelectrode with no optical losses. The attainable current density for a given bandgap is then obtained by integrating the spectral distribution. Starting value is the band gap energy and the integration runs over all shorter wavelengths. If we plot the value of the integral for different starting points w...

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Measurement of the charge separation and injection yields

 The water splitting photocurrent ($J^\mathrm{H_2O} _\textrm{photocurrent}$) is a product of the rate of photon absorption expressed as a current density ($J _\textrm{absorbed}$), the charge separation yield of the photogenerated carriers ($\eta _\textrm{charge separation}$), and charge injection yield to the electrolyte ($\eta _\textrm{charge i...

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