f. Assuming F = 1 give an expression for a critical optical power Pc for which the electrical power delivered to the load P equals the optical power Po incident on the photodiode. It follows that the model predicts p > Po for optical powers Po > Pc in violation of the 1st law of thermodynamics. Explain the reason for the failure of the model. (Hint: evaluate the potential energy qVoc for Po=Pc making use of the expression for the ideal responsivity of a semiconductor photodiode and compare with the energy gap of the semiconductor). 1 In addition to a source of 'heat from a hot reservoir (the incident optical power) and the work done (electrical power delivered to the load), the 2nd law of thermodynamics requires a cold reservoir (the ambient environment) to act as a heat sink. Describe the physical processes responsible for converting the excess energy of the photon into this heat. f. Assuming F = 1 give an expression for a critical optical power Pc for which the electrical power delivered to the load P equals the optical power Po incident on the photodiode. It follows that the model predicts p > Po for optical powers Po > Pc in violation of the 1st law of thermodynamics. Explain the reason for the failure of the model. (Hint: evaluate the potential energy qVoc for Po=Pc making use of the expression for the ideal responsivity of a semiconductor photodiode and compare with the energy gap of the semiconductor). 1 In addition to a source of 'heat from a hot reservoir (the incident optical power) and the work done (electrical power delivered to the load), the 2nd law of thermodynamics requires a cold reservoir (the ambient environment) to act as a heat sink. Describe the physical processes responsible for converting the excess energy of the photon into this heat