New benzodithiophene fused electron acceptors for benzodithiophene-based polymer

Bifunctional Urea–Polyethyleneimine‐Mediated Surface Engineering in SnO2 Electron‐Transport Layer for Efficient and Stable Organic Solar Cells

“…These results suggest that utilizing SnO 2 : u ‐PEIs as the ETL materials leads to superior efficiency in exciton dissociation and charge collection in the devices, resulting in an enhanced FF. [ 67,69 ]…”

“…[64,65] In Figure 4e, J ph increases linearly with an increase in V eff , eventually reaching saturation at a high V eff value, which indicates the complete dissociation of all excitons into free charge carriers. [66,67] The exciton dissociation probability (P diss ) is expressed by P diss = J ph, sc /J sat , where J ph, sc represents the photocurrent density under the short-circuit condition and J sat represents the saturated current density at a high V eff . [68,69] The devices incorporating SnO 2 :u-PEIs exhibit a P diss of 96.7%, clearly surpassing that of bare SnO 2 (94.8%) and slightly exceeding that of SnO 2 :PEI (96.5%).…”

“…SnO 2 :u-PEIs as the ETL materials leads to superior efficiency in exciton dissociation and charge collection in the devices, resulting in an enhanced FF. [67,69] Next, to gain further insight into the impact of urea functionalization on the charge-carrier dynamics in the devices, we conducted transient photocurrent (TPC) measurements. As shown in Figure 4f, the evaluation of the charge-carrier extraction times yielded values of 265.2, 140.3, 135.7, 138.2, and 142.4 ns for devices using SnO 2 , SnO 2 :PEI, SnO 2 :u-PEI10, SnO 2 :u-PEI20, and SnO 2 :u-PEI30 as ETLs, respectively.…”