1. Intensity of incident light: The greater the intensity of the incident light, the greater the number of photons striking the metal surface, and hence, the greater the photoelectric current.

2. Wavelength of incident light: The shorter the wavelength of the incident light, the higher the energy of the photons, and hence, the greater the photoelectric current.

3. Nature of the metal surface: Different metals have different work functions, which means that they require different amounts of energy to emit electrons. Metals with a lower work function will have a higher photoelectric current for a given wavelength of light compared to metals with a higher work function.

4. Applied voltage: If a positive voltage is applied to the anode, it will attract the emitted electrons and increase the photoelectric current. Conversely, if a negative voltage is applied, it will repel the emitted electrons and decrease the photoelectric current.

Understanding these factors is essential for designing and optimizing optoelectronic devices such as solar cells, photodiodes, and photomultipliers.