Help with writing up a bill of sale/reciept (me as the customer) for yard/grass-cutting work....?

I have been so busy with work, that I had been neglectful in keeping up maintanance with the front and back yard of my house. I finally got someone to come by and mow, cut the grass, trim hedges, etc. The person doing it is a young kid in the neighborhood, that is looking for Summer-time work/job. I will pay him tomorrow, but I don't necessarily want to pay him with a " check," because of sensitive information on a check. Would it be ok and more logical if I can write a bill of reciept/sale (for peace of mind) stating that he did the yard work on such-and-such date for such amount....and have both of us sign? This way I have a copy, he has a copy showing proof that I paid him in cash? Can I do that as a customer?....