成果報告書詳細
管理番号20160000000224
タイトル*平成27年度中間年報 「高性能・高信頼性太陽光発電の発電コスト低減技術開発/革新的新構造太陽電池の研究開発/超高効率・低コストIIIーV化合物太陽電池モジュールの研究開発(超高効率セルおよび低コスト化技術開発)」
公開日2016/12/14
報告書年度2015 - 2015
委託先名国立大学法人東京大学
プロジェクト番号P15003
部署名新エネルギー部
和文要約
英文要約Title:Development of high performance and reliable PV modules to reduce levelized cost of energy (Research and Development of innovative new structure solar cells) “Research and Development of ultra-high efficiency and low-cost III-V compound semiconductor solar cell modules (Ultra-high efficiency cells and cost reduction technology)” (FY2015-FY2017) FY2015 Annual Report

It is shown that thickness of each subcell in InGaP/GaAs/InGaAs cell can be reduced by including LC effect while preserving high efficiency. For QD solar cell, photon confinement placed on the rear can increase Isc by 3.97 mA/cm2. Optimized 400nm-thick GaAs/Si tandem cell can achieve 30% and QWs placed in GaAs cell can further improve the efficiency.
Crack-free lift-off of GaAs film from the substrate was achieved by ELO. The first ELO and surface analyzer equipment were developed by Takano.
In collaboration with Taiyo-Nissan, a MOCVD reactor for high-speed growth was designed. The issues associated with high-speed growth was studied in terms of GaAs cell performance and EL technique was developed to characterize GaAs quality.
The post-anneal temperature of GaInNAs:Sb thin films was lowered to 750C and a new wafer shuttle procedure for producing dilute nitride-based 4J cell was studied.
In RF-MBE system, automated K-cell shutter control system was developed and GaInNAs pseudo alloys based on InGaAs:N delta-doped superlattices were fabricated with precise control.
The bandgap of QWs was lowered to 1.15 eV aiming at the 3rd cell of 4-junction cell. A GaAs cell with 70 QWs showed filtered current of 8.5 mA/cm2, just short of the target value. Growth of in-plane nanowire cell structure was optimized and it showed good carrier collection efficiency as compared cell with planar QWs.
Electrical properties were investigated for GaAs/GaAs interface formed by surface-activation bonding. The atomic species employed in the surface cleaning prior to bonding exhibited significant effect and the origin of non-ohmic behavior was related to the crystal defects that were introduced to the GaAs surface upon cleaning.
Low-temperature growth technique of InGaN by pulsed sputtering deposition (PSD) was developed and growth rate as high as 1.2 um/h was achieved. PSD-InGaN growth on lattice-matched ScAlMgO3 (0001) substrate was also studied.
In order to improve the carrier collection efficiency of field-damped QD solar cell, InGaAs QDs embedded by AlAsSb wide-gap material were developed. The cell performance improved because AlAsSb layers successfully suppressed the carrier trapping into QDs.
We have investigated FTIR photocurrent spectra in In(Ga)As QD solar cells and clarified a universal linear relationship on 2 step photon absorption processes for cell design optimization.
The drift-diffusion simulator for QD-IB cell was developed which includes the effect of sequential electron tunneling between confined states of QDs (IB-dots). It is shown that tunneling can reduce recombination rates via IB-dots and improve the cell performance.
PbS QDs with different sizes were synthesized to improve the performance in the near IR region. The cells fabricated with 1300-nm PbS QDs showed EQE onset of approximately 1500 nm. We developed preparation methods for porous nanoparticles, halfshell arrays and nanohole ensembles with plasmon resonances at around 1300 nm.
ダウンロード成果報告書データベース(ユーザ登録必須)から、ダウンロードしてください。

▲トップに戻る