Photovoltaic parameters of mesoscopic perovskite solar cells based on spacer with different building block sizes.

Spacer	Lifetime (ns)	R I (Ω)	J SC (mA cm−2)	V OC (mV)	FF (%)	PCE (%)
No spacer	—	30	16.21	605	66	6.52
S5	0.5	1500	16.06	871	67	9.42
S10	8.4	970	18.26	908	71	11.77
S20	24.1	960	19.10	871	71	11.86
S60	37.2	800	18.19	865	70	11.08
S100	53.7	300	18.62	808	67	10.10