Electronic modulation of adsorption and conductivity in self-assembled interfacial layers for 20.54% (certified 19.93%) efficiency binary organic solar cells

Lei Liu; Shiwen Wu; Jiehao Fu; Peihao Huang; Yaohui Li; Dingqin Hu; Gengsui Tian; Pengyan Zhang; Teng Gu; Heng Liu; Xinhui Lu; Can Wang; Mingyang Gao; Yao Chen; Yang (Michael) Yang; Kuan Sun; Gang Li; Zeyun Xiao

doi:10.1016/j.mattod.2026.103252

Electronic modulation of adsorption and conductivity in self-assembled interfacial layers for 20.54% (certified 19.93%) efficiency binary organic solar cells

Lei Liu (Co-first Author)
, Shiwen Wu (Co-first Author)
, Jiehao Fu^*
, Peihao Huang
, Yaohui Li
, Dingqin Hu
, Gengsui Tian
, Pengyan Zhang
, Teng Gu
, Heng Liu
, Xinhui Lu
, Can Wang
, Mingyang Gao
, Yao Chen^*
, Yang (Michael) Yang
, Kuan Sun
, Gang Li^*
, Zeyun Xiao^*

^*Corresponding author for this work

Department of Mechanical Engineering

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

Abstract

The molecular orientation and adsorption of self-assembled monolayers/multilayers (SAMs) critically govern organic solar cell (OSC) performance via modulating thin-film conductivity. To elucidate this structure–property relationship, we synthesized a new SAM molecule, DM-BZCz, by introducing an electron-donating methoxyphenyl group. This unique molecular design endows DM-BzCz with a preferential vertical molecular orientation on ITO surfaces, leading to enhanced molecular ordering and packing density, as jointly confirmed by theoretical and experimental analyses. The resulting strengthened interfacial dipole promotes more efficient hole extraction, prolongs carrier lifetime, and significantly suppresses interfacial recombination. Consequently, devices based on ITO/SAMs exhibit an increased electrical conductivity from (291.78 S) is superior to that of BZCz (282.45 S), corroborating its superior interfacial characteristics. Therefore, DM-BZCz-based OSCs achieve a significantly improved power conversion efficiency (PCE) of 19.79% compared to the counterparts with methoxyphenyl-free SAMs (18.70%). Using PM1:L8-BO as the photoactive layer, DM-BZCz OSCs attain a remarkable PCE of 20.54% (certified 19.93%), among the highest for binary bulk-heterojunction OSCs. Furthermore, A large-area module (19.3 cm²) delivers a 15.30% PCE employing DM-BZCz SAMs. This work elucidates the structure–property link between SAM electronic structure, adsorption, conductivity, and optoelectronic performance, providing a route to unlock OSC efficiency potential. © 2026 Elsevier Ltd.

Original language	English
Article number	103252
Number of pages	9
Journal	Materials Today
Volume	94
Online published	24 Feb 2026
DOIs	https://doi.org/10.1016/j.mattod.2026.103252
Publication status	Published - May 2026

Funding

National Natural Science Foundation of China (No. 22475211, 22209169, 62305340). Natural Science Foundation of Chongqing (CSTB2024NSCQ-QCXMX0097, CSTB2023NSCQ-MSX0611). Research Grants Council of Hong Kong (CRF C4005 — 22Y, RGC Senior Research Fellowship Scheme SRFS2223-5S01). The authors extend their gratitude to Zhou Yao from Shiyanjia Lab (https://www.shiyanjia.com) for providing invaluable assistance with the HRMS analysis.

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

SDG 7 Affordable and Clean Energy

Research Keywords

Efficiency
Molecular orientation
Organic solar cells
Self-assembled monolayers

RGC Funding Information

RGC-funded

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10.1016/j.mattod.2026.103252

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Liu, L., Wu, S., Fu, J., Huang, P., Li, Y., Hu, D., Tian, G., Zhang, P., Gu, T., Liu, H., Lu, X., Wang, C., Gao, M., Chen, Y., Yang, Y., Sun, K., Li, G., & Xiao, Z. (2026). Electronic modulation of adsorption and conductivity in self-assembled interfacial layers for 20.54% (certified 19.93%) efficiency binary organic solar cells. Materials Today, 94, Article 103252. https://doi.org/10.1016/j.mattod.2026.103252

@article{9536070e14464abc8474b7eead5a1a80,

title = "Electronic modulation of adsorption and conductivity in self-assembled interfacial layers for 20.54\% (certified 19.93\%) efficiency binary organic solar cells",

abstract = "The molecular orientation and adsorption of self-assembled monolayers/multilayers (SAMs) critically govern organic solar cell (OSC) performance via modulating thin-film conductivity. To elucidate this structure–property relationship, we synthesized a new SAM molecule, DM-BZCz, by introducing an electron-donating methoxyphenyl group. This unique molecular design endows DM-BzCz with a preferential vertical molecular orientation on ITO surfaces, leading to enhanced molecular ordering and packing density, as jointly confirmed by theoretical and experimental analyses. The resulting strengthened interfacial dipole promotes more efficient hole extraction, prolongs carrier lifetime, and significantly suppresses interfacial recombination. Consequently, devices based on ITO/SAMs exhibit an increased electrical conductivity from (291.78 S) is superior to that of BZCz (282.45 S), corroborating its superior interfacial characteristics. Therefore, DM-BZCz-based OSCs achieve a significantly improved power conversion efficiency (PCE) of 19.79\% compared to the counterparts with methoxyphenyl-free SAMs (18.70\%). Using PM1:L8-BO as the photoactive layer, DM-BZCz OSCs attain a remarkable PCE of 20.54\% (certified 19.93\%), among the highest for binary bulk-heterojunction OSCs. Furthermore, A large-area module (19.3 cm2) delivers a 15.30\% PCE employing DM-BZCz SAMs. This work elucidates the structure–property link between SAM electronic structure, adsorption, conductivity, and optoelectronic performance, providing a route to unlock OSC efficiency potential. {\textcopyright} 2026 Elsevier Ltd.",

keywords = "Efficiency, Molecular orientation, Organic solar cells, Self-assembled monolayers",

author = "Lei Liu and Shiwen Wu and Jiehao Fu and Peihao Huang and Yaohui Li and Dingqin Hu and Gengsui Tian and Pengyan Zhang and Teng Gu and Heng Liu and Xinhui Lu and Can Wang and Mingyang Gao and Yao Chen and Yang, \{Yang (Michael)\} and Kuan Sun and Gang Li and Zeyun Xiao",

year = "2026",

month = may,

doi = "10.1016/j.mattod.2026.103252",

language = "English",

volume = "94",

journal = "Materials Today",

issn = "1369-7021",

publisher = "Elsevier B.V.",

}

Liu, L, Wu, S, Fu, J, Huang, P, Li, Y, Hu, D, Tian, G, Zhang, P, Gu, T, Liu, H, Lu, X, Wang, C, Gao, M, Chen, Y, Yang, Y, Sun, K, Li, G & Xiao, Z 2026, 'Electronic modulation of adsorption and conductivity in self-assembled interfacial layers for 20.54% (certified 19.93%) efficiency binary organic solar cells', Materials Today, vol. 94, 103252. https://doi.org/10.1016/j.mattod.2026.103252

Electronic modulation of adsorption and conductivity in self-assembled interfacial layers for 20.54% (certified 19.93%) efficiency binary organic solar cells. / Liu, Lei (Co-first Author); Wu, Shiwen (Co-first Author); Fu, Jiehao et al.
In: Materials Today, Vol. 94, 103252, 05.2026.

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

TY - JOUR

T1 - Electronic modulation of adsorption and conductivity in self-assembled interfacial layers for 20.54% (certified 19.93%) efficiency binary organic solar cells

AU - Liu, Lei

AU - Wu, Shiwen

AU - Fu, Jiehao

AU - Huang, Peihao

AU - Li, Yaohui

AU - Hu, Dingqin

AU - Tian, Gengsui

AU - Zhang, Pengyan

AU - Gu, Teng

AU - Liu, Heng

AU - Lu, Xinhui

AU - Wang, Can

AU - Gao, Mingyang

AU - Chen, Yao

AU - Yang, Yang (Michael)

AU - Sun, Kuan

AU - Li, Gang

AU - Xiao, Zeyun

PY - 2026/5

Y1 - 2026/5

N2 - The molecular orientation and adsorption of self-assembled monolayers/multilayers (SAMs) critically govern organic solar cell (OSC) performance via modulating thin-film conductivity. To elucidate this structure–property relationship, we synthesized a new SAM molecule, DM-BZCz, by introducing an electron-donating methoxyphenyl group. This unique molecular design endows DM-BzCz with a preferential vertical molecular orientation on ITO surfaces, leading to enhanced molecular ordering and packing density, as jointly confirmed by theoretical and experimental analyses. The resulting strengthened interfacial dipole promotes more efficient hole extraction, prolongs carrier lifetime, and significantly suppresses interfacial recombination. Consequently, devices based on ITO/SAMs exhibit an increased electrical conductivity from (291.78 S) is superior to that of BZCz (282.45 S), corroborating its superior interfacial characteristics. Therefore, DM-BZCz-based OSCs achieve a significantly improved power conversion efficiency (PCE) of 19.79% compared to the counterparts with methoxyphenyl-free SAMs (18.70%). Using PM1:L8-BO as the photoactive layer, DM-BZCz OSCs attain a remarkable PCE of 20.54% (certified 19.93%), among the highest for binary bulk-heterojunction OSCs. Furthermore, A large-area module (19.3 cm2) delivers a 15.30% PCE employing DM-BZCz SAMs. This work elucidates the structure–property link between SAM electronic structure, adsorption, conductivity, and optoelectronic performance, providing a route to unlock OSC efficiency potential. © 2026 Elsevier Ltd.

AB - The molecular orientation and adsorption of self-assembled monolayers/multilayers (SAMs) critically govern organic solar cell (OSC) performance via modulating thin-film conductivity. To elucidate this structure–property relationship, we synthesized a new SAM molecule, DM-BZCz, by introducing an electron-donating methoxyphenyl group. This unique molecular design endows DM-BzCz with a preferential vertical molecular orientation on ITO surfaces, leading to enhanced molecular ordering and packing density, as jointly confirmed by theoretical and experimental analyses. The resulting strengthened interfacial dipole promotes more efficient hole extraction, prolongs carrier lifetime, and significantly suppresses interfacial recombination. Consequently, devices based on ITO/SAMs exhibit an increased electrical conductivity from (291.78 S) is superior to that of BZCz (282.45 S), corroborating its superior interfacial characteristics. Therefore, DM-BZCz-based OSCs achieve a significantly improved power conversion efficiency (PCE) of 19.79% compared to the counterparts with methoxyphenyl-free SAMs (18.70%). Using PM1:L8-BO as the photoactive layer, DM-BZCz OSCs attain a remarkable PCE of 20.54% (certified 19.93%), among the highest for binary bulk-heterojunction OSCs. Furthermore, A large-area module (19.3 cm2) delivers a 15.30% PCE employing DM-BZCz SAMs. This work elucidates the structure–property link between SAM electronic structure, adsorption, conductivity, and optoelectronic performance, providing a route to unlock OSC efficiency potential. © 2026 Elsevier Ltd.

KW - Efficiency

KW - Molecular orientation

KW - Organic solar cells

KW - Self-assembled monolayers

UR - https://www.scopus.com/pages/publications/105030936417

UR - https://www.scopus.com/record/pubmetrics.uri?eid=2-s2.0-105030936417&origin=recordpage

U2 - 10.1016/j.mattod.2026.103252

DO - 10.1016/j.mattod.2026.103252

M3 - RGC 21 - Publication in refereed journal

SN - 1369-7021

VL - 94

JO - Materials Today

JF - Materials Today

M1 - 103252

ER -

Electronic modulation of adsorption and conductivity in self-assembled interfacial layers for 20.54% (certified 19.93%) efficiency binary organic solar cells

Abstract

Funding

UN SDGs

Research Keywords

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YCRG-ExtU-Lead: Fundamental-Studies-Guided Growing of High-Quality, Mechanically Stable, Reduced-Dimensional Perovskites for Scalable Flexible Optoelectronic Devices

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Electronic modulation of adsorption and conductivity in self-assembled interfacial layers for 20.54% (certified 19.93%) efficiency binary organic solar cells

Abstract

Funding

UN SDGs

Research Keywords

RGC Funding Information

Access Output

Other Access Options

Permanent Link

Other Files and Links

Fingerprint

Projects

YCRG-ExtU-Lead: Fundamental-Studies-Guided Growing of High-Quality, Mechanically Stable, Reduced-Dimensional Perovskites for Scalable Flexible Optoelectronic Devices

Cite this