DASH（Dopant-free Asymmetric Heterocontacts）电池是一种无掺杂无pn结的新型异质结电池，其利用对一种载流子形成传输层而对另一载流子形成高势垒阻挡层的金半接触来分离和收集载流子，可以避免由掺杂而引起的寄生光学吸收、俄歇复合等诸多效率损失。针对DASH电池的电子传输层/晶体硅界面存在严重载流子复合损失的难题，本项目提出了一种具有MoOx/a-Si:H(i)/c-Si(n)/SiOx/LiFx/Al结构的新型DASH电池，将带有固定电荷的超薄氧化层插入电子传输层/晶体硅界面作为界面钝化和电子隧穿层。具有场钝化效应的超薄氧化层与具有更低功函数的LiFx/Al电子传输层结合，使电子传输层/晶体硅界的场钝化叠加，会产生比单一高低结或者金-半接触更大的能带弯曲和空穴势垒，比现有DASH电池和TOPcon电池更加抑制空穴在n型体硅衬底背面的界面复合，有望提高效率。

DASH (Dopant-free Asymmetric Heterocontacts) solar cell, which is a hot spot in the solar research field in 2016, is not based on p-n junction and consists of two different metal-semiconductor heterocontacts. These two complementary carrier-selective heterocontacts provide a negligible resistance to the collected carrier (synonymous with a low contact resistivity) whilst simultaneously ‘blocking’ the other carrier (equivalent to low contact recombination) via either conduction or valence band barrier. DASH solar cells can avoid drawbacks of mainstream doped pn junctions such as doping-induced parasitic absorption, Auger recombination and other heavy doping effect. To overcome the issue of serious carrier recombination losses at the interface of electron-selective heterocontact, a DASH solar cell with the new MoOx/a-Si:H(i)/c-Si(n)/SiOx/LiFx/Al structure is proposed by inserting the ultra-thin tunneling SiOx film with fixed charges as the passivation layer at c-Si(n)/LiFx/Al interface. Combined with the presence of field passivation effect induced by LiFx/Al electron-selective layer due to its low work function, the additional field passivation effect of tunneling SiOx would lead to the large valence band bending than single high-low junction or schottky junction, and further block the flow of holes via the higher valence band barrier compared with HIT, TOPcon and the present DASH solar cells, suppressing the carrier recombination and thus further improving Voc and efficiency. In addtion, the combination of LiFx/Al ohmic contact and ultra-thin SiOx with high electron tunneling efficiency also further reduces the contact resistivity of electron-selective layer.