Maturing Effects in Carbon‐Based Perovskite Solar Cells: Understanding and Consequences on Photovoltaic Performances

Abstract

Recent investigations have highlighted the potential of posttreatments to enhance the performance of specific perovskite solar cells (PSCs), notably focusing on those incorporating carbon‐based materials (C‐PSC). However, the precise mechanisms underpinning this performance boost remain somewhat elusive. This study aims to delve deeper into the maturation phenomenon observed in C‐PSC, concentrating on two distinct methods of perovskite deposition: drop casting and inkjet printing. Upon subjecting the cells to the maturation process, elevation in power conversion efficiency (PCE) becomes evident. Specifically, drop‐cast cells exhibit a PCE advancement from 10.5% to 14%, while inkjet‐printed cells showcase an improvement from 10% to 14%. In the context of drop‐cast cells, characterized by a relatively thicker and spatially heterogeneous perovskite layer, maturation prompts alterations within the perovskite layer itself. Conversely, in the realm of inkjet solar cells boasting a thinner yet more uniform active layer thickness, maturation exerts distinctive impacts, primarily manifesting at the interfaces. The observed maturation phenomenon exhibits a dependence on the solar cell's architecture and morphology, underscoring the pivotal role of these aspects in determining the ensuing effects. These revelations offer illuminating insights into the intricate dynamics of PSCs and offer valuable guidance for the ongoing refinement of their performance.

Performance Evaluation of Printable Carbon‐Based Perovskite Solar Cells Infiltrated with Reusable CsPbI3:EuCl3 and Standard AVA‐MAPbI3

“…Such a bump was previously reported in other works where a low scan rate was used for the measurements (4 mV s −1 ). [ 22 ] On the contrary, the J – V curves of CsPbI 3 :EuCl 3 mC‐PSCs (Figure 2b) are not as sensitive as AVA‐MAPbI 3 mC‐PSCs to the change in the scan rate, with close hysteresis indexes at the two scan rates (9.8% at 50 mV s −1 and 12.2% at 6 mV s −1 ).…”

“…In ref. [22], devices with 150 mm 2 area exhibited efficiency of 7.35% (scan rate 4 mV s −1 ), bump included (or 6.3% estimated by excluding the bump) to be compared with 144 mm 2 area shown in this work with efficiency 5.59% (without bump). By performing long‐lasting humidity thermal treatments higher efficiencies can be achieved (10% estimated by excluding the bump, on 150 mm 2 area devices).…”

“…By performing long‐lasting humidity thermal treatments higher efficiencies can be achieved (10% estimated by excluding the bump, on 150 mm 2 area devices). [ 22 ] In ref. [34] manual drop casting processes are applied, and 5.63% efficiency is generated in 50 mm 2 area devices (scan rate 20 mV s −1 , no bump).…”

“…To further investigate the hysteresis phenomenon in mC-PSCs, we performed J-V measurements at a lower scan rate, specifically at 6 mV s À1 , similar to the value used in the literature for the same device architecture (4 mV s À1 ). [22,26] Figure 2a compares the J-V curves of AVA-MAPbI 3 mC-PSC acquired on the same device, firstly biased at the step of 50 mV s À1 and after at the step of 6 mV s À1 . All the PV parameters change by varying the scan rate, as shown in Table 1.…”

“…[ 21 ] The last two methods guarantee a better layer uniformity than manual drop‐casting, and thus higher efficiency on large‐area devices. [ 22 ]…”