We investigate photocurrent generation in undoped $\mathrm{GaAs}/\mathrm{A}{\mathrm{l}}_{0.3}\mathrm{G}{\mathrm{a}}_{0.7}\mathrm{As}$ multiple quantum wells at room temperature using spatially resolved photocurrent mapping. Under linearly polarized excitation, the response is dominated by the photothermoelectric effect. In contrast, helicity-dependent maps under circularly polarized light reveal two transverse spin-related contributions: a photoinduced anomalous Hall effect (PAHE) and a spin Nernst effect (SNE). With a transverse bias, spin-polarized carriers generated by circularly polarized light are transported in the presence of temperature gradients and converted to charge signals via the inverse spin Hall effect, producing photocurrent at the electrodes and within the device interior. The PAHE is consistent with spin-dependent deflection, whereas the SNE arises from thermally driven spin accumulation. Both contributions scale approximately linearly with the applied optical power over the measured ranges. These results clarify transverse spin transport in GaAs-based quantum wells and inform the design of III-V spintronic photodetectors.

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• Photocurrent
• Photoinduced effect
• Spin optoelectronics
• Spin-orbit coupling
• Annealing
• Molecular beam epitaxy
• Photoexcitation
• Photoluminescence
• Polarized optical microscopy
• Resistivity measurements
• Welding