fig7

Figure 7. (A) Thermal aging of unencapsulated devices under N₂ at 80 °C; (B) Ambient storage stability of unencapsulated devices at approximately 25 °C and 30-35% RH. PU-L: Sample prepared using a Pb(NO₃)₂ precursor containing 0.3 mg/mL urea; PUS-L: the corresponding sample after additional heat treatment at 150 °C for 20 min; RH: relative humidity.