TY - JOUR
T1 - Bulk-heterojunction solar cells with enriched polymer contents
AU - Yin, Hang
AU - Chiu, Ka Lok
AU - Ho, Carr Hoi Yi
AU - Lee, Harrison Ka Hin
AU - Li, Ho Wa
AU - Cheng, Yuanhang
AU - Tsang, Sai Wing
AU - So, Shu Kong
PY - 2017/1/1
Y1 - 2017/1/1
N2 - In a high performance PTB7:PC71BM bulk-heterojunction (BHJ) solar cell, the commonly optimized polymer:fullerene (D:A) weight ratio is about 1:1.5, when PC71BM is used as the acceptor. This report explores alternative D:A weight ratios. We describe how to enrich the polymer contents of these BHJ solar cells to achieve high power conversion efficiencies (PCEs). The concentration of 1,8-diiodooctane (DIO), a solvent additive for the BHJ precursor solutions, is increased in order to re-optimize the BHJ cells. The PCEs of the re-optimized cells are improved for the PTB7 cells. Detailed charge transport measurements were carried out to examine the polymer-rich BHJs. We observed enhanced hole mobilities for the PTB7 BHJs. Additionally, the electron mobilities are preserved due to the dispersion of fullerene domains by increased DIO concentrations. Two other well-known polymer donors PCDTBT and PDTSTPD have been also investigated, and the improvements of hole mobilities and PCEs can be obtained for both polymer-rich BHJ solar cells.
AB - In a high performance PTB7:PC71BM bulk-heterojunction (BHJ) solar cell, the commonly optimized polymer:fullerene (D:A) weight ratio is about 1:1.5, when PC71BM is used as the acceptor. This report explores alternative D:A weight ratios. We describe how to enrich the polymer contents of these BHJ solar cells to achieve high power conversion efficiencies (PCEs). The concentration of 1,8-diiodooctane (DIO), a solvent additive for the BHJ precursor solutions, is increased in order to re-optimize the BHJ cells. The PCEs of the re-optimized cells are improved for the PTB7 cells. Detailed charge transport measurements were carried out to examine the polymer-rich BHJs. We observed enhanced hole mobilities for the PTB7 BHJs. Additionally, the electron mobilities are preserved due to the dispersion of fullerene domains by increased DIO concentrations. Two other well-known polymer donors PCDTBT and PDTSTPD have been also investigated, and the improvements of hole mobilities and PCEs can be obtained for both polymer-rich BHJ solar cells.
KW - Admittance spectroscopy
KW - Charge transport
KW - Donor:acceptor ratio
KW - PCE
UR - http://www.scopus.com/inward/record.url?scp=84994371500&partnerID=8YFLogxK
UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-84994371500&origin=recordpage
U2 - 10.1016/j.orgel.2016.10.030
DO - 10.1016/j.orgel.2016.10.030
M3 - RGC 21 - Publication in refereed journal
SN - 1566-1199
VL - 40
SP - 1
EP - 7
JO - Organic Electronics: physics, materials, applications
JF - Organic Electronics: physics, materials, applications
ER -
