Perovskite solar cells (PSCs) have attracted significant attention in recent years due to the rapid increase in device efficiency (reaching over 25% in 2019), ease of fabrication, and the potential to produce low-cost photovoltaic modules. In this paper we have determined the ideal power conversion efficiency and quantum efficiency of PSCs with the p-i-n device structure, where p is the hole transport layer, i is the perovskite absorber layer, and n is the electron transport layer. The absorption of incident light occurs in a thin perovskite layer, the thickness of which is comparable to the wavelength of absorbed light. We take into account interference effects when the PSC structure is represented by a Fabry-Perot resonator. The optical flux within the absorbing layer is calculated as a function of the spatial coordinate (in the direction of the layer thickness), for a certain wavelength, at the normal incident light. The power quantum efficiency is calculated assuming that the incident light source is a blackbody at the temperature of the Sun, as well as for the AM1.5g standard solar spectrum. The results obtained by using the derived expressions that take into account the interference effects are compared with those obtained by neglecting these effects.