Flexible, highly efficient all-polymer solar cells

Abstract

All-polymer solar cells have shown great potential as flexible and portable power generators. These devices should offer good mechanical endurance with high power-conversion efficiency for viability in commercial applications. In this work, we develop highly efficient and mechanically robust all-polymer solar cells that are based on the PBDTTTPD polymer donor and the P(NDI2HD-T) polymer acceptor. These systems exhibit high power-conversion efficiency of 6.64%. Also, the proposed all-polymer solar cells have even better performance than the control polymer-fullerene devices with phenyl-C61-butyric acid methyl ester (PCBM) as the electron acceptor (6.12%). More importantly, our all-polymer solar cells exhibit dramatically enhanced strength and flexibility compared with polymer/PCBM devices, with 60- and 470-fold improvements in elongation at break and toughness, respectively. The superior mechanical properties of all-polymer solar cells afford greater tolerance to severe deformations than conventional polymer-fullerene solar cells, making them much better candidates for applications in flexible and portable devices.

8.0% Efficient All‐Polymer Solar Cells with High Photovoltage of 1.1 V and Internal Quantum Efficiency near Unity

“…[39] PNDI-T shows a M w of 78.5 kDa with a PDI of 1.9, which is comparable to the previous reports in literature. [29,40] All the three polymers present good thermal stability as revealed by thermogravimetric analysis (TGA) with decomposition temperature over 300 °C ( Figure S2a, Supporting Information). Differential scanning calorimetry (DSC) reveals that the two donor polymers exhibit no clear thermal transitions along the heating and cooling cycle, suggesting that they are mostly amorphous in the solid state ( Figure S2b, Supporting Information).…”

“…[53] The measured mobilities of the PBDT-TPD:PNDI-T and PBDT-TPD:PC 71 BM solar cells are also in good agreement with the previous reports in literature. [29,54] …”

“…The high-performance all-PSCs with PCEs over 7% only afford moderate V oc around 0.8 V, [18,22,24,26,28] whereas a few all-PSCs can emerge high V oc around 1.0 V, but the PCEs never surpass 7%. [20,[29][30][31][32] In contrast, a PC 71 BM-based PSC with a high V oc close to 1 V and a high PCE of 8.9% has been realized. [33] A nonfullerene PSC based on a polymer/small molecule blend also attained a high V oc of 1.12 V with a high PCE approaching 10%.…”

“…Moreover, better photovoltaic performance and mechanical durability of the all-PSCs were found as compared to the PC 71 BM-based PSCs, which highlighted the potential of all-PSCs for wearable and portable applications. [29] In order to take full advantages of all-PSCs, it is essential to find rational combinations of donor and acceptor polymers, so that both the V oc and other device parameters can be simultaneously improved. [13,14] In this contribution, we report an all-PSC using an alkylthiosubstituted polymer poly [4,8- (Figure 1).…”

Ternary Blend of Conjugated Polymers for Broadening the Absorption Bandwidth of Polymer Solar Cells

“…These properties of the polymer/polymer blend system are greatly beneficial for future applications in portable and wearable devices that require both high performances and mechanical stability [1]. Therefore, polymer/polymer blend solar cells have recently received considerable attention and significant strides have been made in improving their power conversion efficiencies (PCEs) [2][3][4][5][6][7][8].…”