Improvement in open circuit voltage of n‐ZnO/p‐Si solar cell by using amorphous‐ZnO at the interface

Abstract

Several research groups are currently working on n-ZnO/p-Si heterojunction solar cell, and recently, Pietruszka et al [Sol. Energ. Mat. Sol. Cells 147 (2016) 164-170] has reported the highest efficiency of 7.1% for this structure. The main challenge is to enhance the open circuit voltage up to theoretically predicted value of >0.6 V. This paper reports >20% improvement in open circuit voltage of n-ZnO/p-Si solar cell by depositing amorphous-ZnO at the interface at room temperature that possibly improves the passivation and/or avoids oxide formation at the interface during ZnO deposition. Two other materials, aluminum nitride and amorphous-Si, have also been used as buffer layers to evaluate their effect on suppression of interface states. Furthermore, additional advantage of ZnO as an antireflector has been experimentally verified for different thicknesses of ZnO film.

Electron Affinity and Bandgap Optimization of Zinc Oxide for Improved Performance of ZnO/Si Heterojunction Solar Cell Using PC1D Simulations

“…It was anticipated that an overall conversion efficiency of 19% and fill factor of 81% can be achieved using the proposed structure. Following this, several groups reported different experimental results [8][9][10][11][12] for the n-ZnO/p-Si solar cell with the best efficiency of 14% achieved by Pietruszka et al recently [13]. Also, few groups have recently reported simulation results optimizing different parameters of ZnO/Si solar cell.…”

Tantalum Nitride Electron‐Selective Contact for Crystalline Silicon Solar Cells

“…However, the ultrathin films suffer from poor stability during metallization, and no obvious efficiency improvement has been achieved on a device level. A series of thin films with extremely low or high work function and/or suitable band offsets with silicon ( Figure 1 ) were recently investigated as potential DF‐CSCs for c‐Si solar cells . For example, thin films with either a high work function (e.g., MoO x ) or a small valence band offset with silicon (e.g., CuO) (see Figure , left side) were developed as hole‐selective contacts.…”

“…Thin films with a low work function (e.g., LiF, Mg) or a small conduction band offset with silicon (e.g., TiO 2 ) were also developed as electron‐selective contacts. Using a high‐performance hole‐selective MoO x contact or an electron‐selective TiO 2 contact, c‐Si solar cells with efficiencies more than 22% were achieved. By combining MoO x and LiF/Al contacts, a dopant‐free asymmetric heterocontact c‐Si solar cell with a PCE close to 20% was achieved with a simple fabrication flow .…”

“…A series of thin films with extremely low or high work function and/or suitable band offsets with silicon (Figure 1) were recently investigated as potential DF-CSCs for c-Si solar cells. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26] For example, thin films with either a high work function (e.g., MoO x ) or a small valence band offset with silicon (e.g., CuO) (see Figure 1, left side) were developed as holeselective contacts. Thin films with a low work function (e.g., LiF, Mg) or a small conduction band offset with silicon (e.g., TiO 2 ) were also developed as electron-selective contacts.…”

Multipeak Emissions and Electrical Properties of ZnO/Si Heterojunctions Based on ZnO Nanoflakes by Spin Coating Technique

“…Based on the p-type silicon, ZnO has been used as an n-type material to fabricate the ZnO/Si heterojunctions. Solar cells based on ZnO/Si heterojunctions have been researched extensively by many groups, and some exciting results have been obtained [8][9][10]. But the efficiency of photovoltaic devices based on ZnO/Si heterojunctions is still unsatisfactory.…”