用于溶液处理体异质结有机太阳能电池的非对称供体-受体-受体-π-供体型苯并噻二唑基小分子

Unsymmetrical Donor-Acceptor-Acceptor-π-Donor Type Benzothiadiazole-Based Small Molecule for a Solution Processed Bulk Heterojunction Organic Solar Cell.

作者信息

Gautam Prabhat, Misra Rajneesh, Siddiqui Shahbaz A, Sharma Ganesh D

机构信息

†Department of Chemistry, Indian Institute of Technology, Indore, Madhya Pradesh 452017, India.

‡Department of Electrical Engineering, Vivekanand Institute of Technology, Jagatpura, Jaipur, Rajasthan 302025, India.

出版信息

ACS Appl Mater Interfaces. 2015 May 20;7(19):10283-92. doi: 10.1021/acsami.5b02250. Epub 2015 May 6.

DOI:10.1021/acsami.5b02250

PMID:25946406

Abstract

A D1-A-A'-π-D2 type (D = donor; A = acceptor) unsymmetrical small molecule denoted as BTD3 containing different end group donor moieties has been designed and synthesized for use as a donor in the solution processable bulk heterojunction (BHJ) solar cell. The BTD3 exhibits a low HOMO-LUMO gap of 1.68 eV and deeper HOMO energy level (-5.5 eV). Its LUMO energy level (-3.65 eV) is compatible with the LUMO level of PC71BM to facilitate the electron transfer from BTD3 to PC71BM in the BHJ solar cell. The solution processed BHJ solar cell with optimized BTD3:PC71BM active layer processed with THF solvent exhibited a PCE of 3.15% with Jsc = 7.45 mA/cm(2), Voc = 0.94 V, and FF = 0.45. Moreover, the device with optimized concentration of 3 vol. % 1-chloronaphthalene (CN) additive, i.e., CN/THF, showed significant enhancement in PCE up to 4.61% (Jsc = 9.48 mA/cm(2), Voc = 0.90 V, and FF = 0.54). The improvement in the PCE has been attributed to the appropriate nanoscale phase separation morphology, balance charge transport, and enhancement in the light harvesting ability of the active layer.

摘要

一种D1-A-A'-π-D2型（D = 给体；A = 受体）不对称小分子，记为BTD3，其含有不同的端基给体部分，已被设计并合成出来，用作溶液可加工体异质结（BHJ）太阳能电池中的给体。BTD3表现出1.68 eV的低HOMO-LUMO能隙和更深的HOMO能级（-5.5 eV）。其LUMO能级（-3.65 eV）与PC71BM的LUMO能级相匹配，以促进BHJ太阳能电池中从BTD3到PC71BM的电子转移。用THF溶剂加工的具有优化的BTD3:PC71BM活性层的溶液加工BHJ太阳能电池，其PCE为3.15%，Jsc = 7.45 mA/cm²，Voc = 0.94 V，FF = 0.45。此外，含有3体积% 1-氯萘（CN）添加剂（即CN/THF）的优化浓度的器件，其PCE显著提高至4.61%（Jsc = 9.48 mA/cm²，Voc = 0.90 V，FF = 0.54）。PCE的提高归因于合适的纳米级相分离形态、平衡的电荷传输以及活性层光捕获能力的增强。